diff --git a/configure b/configure
index 575fb1d704..576c9cd9b1 100755
--- a/configure
+++ b/configure
@@ -1,9 +1,10 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.69 for PLUMED 2.
+# Generated by GNU Autoconf 2.72 for PLUMED 2.
 #
 #
-# Copyright (C) 1992-1996, 1998-2012 Free Software Foundation, Inc.
+# Copyright (C) 1992-1996, 1998-2017, 2020-2023 Free Software Foundation,
+# Inc.
 #
 #
 # This configure script is free software; the Free Software Foundation
@@ -14,63 +15,65 @@
 
 # Be more Bourne compatible
 DUALCASE=1; export DUALCASE # for MKS sh
-if test -n "${ZSH_VERSION+set}" && (emulate sh) >/dev/null 2>&1; then :
+if test ${ZSH_VERSION+y} && (emulate sh) >/dev/null 2>&1
+then :
   emulate sh
   NULLCMD=:
   # Pre-4.2 versions of Zsh do word splitting on ${1+"$@"}, which
   # is contrary to our usage.  Disable this feature.
   alias -g '${1+"$@"}'='"$@"'
   setopt NO_GLOB_SUBST
-else
-  case `(set -o) 2>/dev/null` in #(
+else case e in #(
+  e) case `(set -o) 2>/dev/null` in #(
   *posix*) :
     set -o posix ;; #(
   *) :
      ;;
+esac ;;
 esac
 fi
 
 
+
+# Reset variables that may have inherited troublesome values from
+# the environment.
+
+# IFS needs to be set, to space, tab, and newline, in precisely that order.
+# (If _AS_PATH_WALK were called with IFS unset, it would have the
+# side effect of setting IFS to empty, thus disabling word splitting.)
+# Quoting is to prevent editors from complaining about space-tab.
 as_nl='
 '
 export as_nl
-# Printing a long string crashes Solaris 7 /usr/bin/printf.
-as_echo='\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\'
-as_echo=$as_echo$as_echo$as_echo$as_echo$as_echo
-as_echo=$as_echo$as_echo$as_echo$as_echo$as_echo$as_echo
-# Prefer a ksh shell builtin over an external printf program on Solaris,
-# but without wasting forks for bash or zsh.
-if test -z "$BASH_VERSION$ZSH_VERSION" \
-    && (test "X`print -r -- $as_echo`" = "X$as_echo") 2>/dev/null; then
-  as_echo='print -r --'
-  as_echo_n='print -rn --'
-elif (test "X`printf %s $as_echo`" = "X$as_echo") 2>/dev/null; then
-  as_echo='printf %s\n'
-  as_echo_n='printf %s'
-else
-  if test "X`(/usr/ucb/echo -n -n $as_echo) 2>/dev/null`" = "X-n $as_echo"; then
-    as_echo_body='eval /usr/ucb/echo -n "$1$as_nl"'
-    as_echo_n='/usr/ucb/echo -n'
-  else
-    as_echo_body='eval expr "X$1" : "X\\(.*\\)"'
-    as_echo_n_body='eval
-      arg=$1;
-      case $arg in #(
-      *"$as_nl"*)
-	expr "X$arg" : "X\\(.*\\)$as_nl";
-	arg=`expr "X$arg" : ".*$as_nl\\(.*\\)"`;;
-      esac;
-      expr "X$arg" : "X\\(.*\\)" | tr -d "$as_nl"
-    '
-    export as_echo_n_body
-    as_echo_n='sh -c $as_echo_n_body as_echo'
-  fi
-  export as_echo_body
-  as_echo='sh -c $as_echo_body as_echo'
-fi
+IFS=" ""	$as_nl"
+
+PS1='$ '
+PS2='> '
+PS4='+ '
+
+# Ensure predictable behavior from utilities with locale-dependent output.
+LC_ALL=C
+export LC_ALL
+LANGUAGE=C
+export LANGUAGE
+
+# We cannot yet rely on "unset" to work, but we need these variables
+# to be unset--not just set to an empty or harmless value--now, to
+# avoid bugs in old shells (e.g. pre-3.0 UWIN ksh).  This construct
+# also avoids known problems related to "unset" and subshell syntax
+# in other old shells (e.g. bash 2.01 and pdksh 5.2.14).
+for as_var in BASH_ENV ENV MAIL MAILPATH CDPATH
+do eval test \${$as_var+y} \
+  && ( (unset $as_var) || exit 1) >/dev/null 2>&1 && unset $as_var || :
+done
+
+# Ensure that fds 0, 1, and 2 are open.
+if (exec 3>&0) 2>/dev/null; then :; else exec 0</dev/null; fi
+if (exec 3>&1) 2>/dev/null; then :; else exec 1>/dev/null; fi
+if (exec 3>&2)            ; then :; else exec 2>/dev/null; fi
 
 # The user is always right.
-if test "${PATH_SEPARATOR+set}" != set; then
+if ${PATH_SEPARATOR+false} :; then
   PATH_SEPARATOR=:
   (PATH='/bin;/bin'; FPATH=$PATH; sh -c :) >/dev/null 2>&1 && {
     (PATH='/bin:/bin'; FPATH=$PATH; sh -c :) >/dev/null 2>&1 ||
@@ -79,13 +82,6 @@ if test "${PATH_SEPARATOR+set}" != set; then
 fi
 
 
-# IFS
-# We need space, tab and new line, in precisely that order.  Quoting is
-# there to prevent editors from complaining about space-tab.
-# (If _AS_PATH_WALK were called with IFS unset, it would disable word
-# splitting by setting IFS to empty value.)
-IFS=" ""	$as_nl"
-
 # Find who we are.  Look in the path if we contain no directory separator.
 as_myself=
 case $0 in #((
@@ -94,43 +90,27 @@ case $0 in #((
 for as_dir in $PATH
 do
   IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
-    test -r "$as_dir/$0" && as_myself=$as_dir/$0 && break
+  case $as_dir in #(((
+    '') as_dir=./ ;;
+    */) ;;
+    *) as_dir=$as_dir/ ;;
+  esac
+    test -r "$as_dir$0" && as_myself=$as_dir$0 && break
   done
 IFS=$as_save_IFS
 
      ;;
 esac
-# We did not find ourselves, most probably we were run as `sh COMMAND'
+# We did not find ourselves, most probably we were run as 'sh COMMAND'
 # in which case we are not to be found in the path.
 if test "x$as_myself" = x; then
   as_myself=$0
 fi
 if test ! -f "$as_myself"; then
-  $as_echo "$as_myself: error: cannot find myself; rerun with an absolute file name" >&2
+  printf "%s\n" "$as_myself: error: cannot find myself; rerun with an absolute file name" >&2
   exit 1
 fi
 
-# Unset variables that we do not need and which cause bugs (e.g. in
-# pre-3.0 UWIN ksh).  But do not cause bugs in bash 2.01; the "|| exit 1"
-# suppresses any "Segmentation fault" message there.  '((' could
-# trigger a bug in pdksh 5.2.14.
-for as_var in BASH_ENV ENV MAIL MAILPATH
-do eval test x\${$as_var+set} = xset \
-  && ( (unset $as_var) || exit 1) >/dev/null 2>&1 && unset $as_var || :
-done
-PS1='$ '
-PS2='> '
-PS4='+ '
-
-# NLS nuisances.
-LC_ALL=C
-export LC_ALL
-LANGUAGE=C
-export LANGUAGE
-
-# CDPATH.
-(unset CDPATH) >/dev/null 2>&1 && unset CDPATH
 
 # Use a proper internal environment variable to ensure we don't fall
   # into an infinite loop, continuously re-executing ourselves.
@@ -151,26 +131,28 @@ case $- in # ((((
 esac
 exec $CONFIG_SHELL $as_opts "$as_myself" ${1+"$@"}
 # Admittedly, this is quite paranoid, since all the known shells bail
-# out after a failed `exec'.
-$as_echo "$0: could not re-execute with $CONFIG_SHELL" >&2
-as_fn_exit 255
+# out after a failed 'exec'.
+printf "%s\n" "$0: could not re-execute with $CONFIG_SHELL" >&2
+exit 255
   fi
   # We don't want this to propagate to other subprocesses.
           { _as_can_reexec=; unset _as_can_reexec;}
 if test "x$CONFIG_SHELL" = x; then
-  as_bourne_compatible="if test -n \"\${ZSH_VERSION+set}\" && (emulate sh) >/dev/null 2>&1; then :
+  as_bourne_compatible="if test \${ZSH_VERSION+y} && (emulate sh) >/dev/null 2>&1
+then :
   emulate sh
   NULLCMD=:
   # Pre-4.2 versions of Zsh do word splitting on \${1+\"\$@\"}, which
   # is contrary to our usage.  Disable this feature.
   alias -g '\${1+\"\$@\"}'='\"\$@\"'
   setopt NO_GLOB_SUBST
-else
-  case \`(set -o) 2>/dev/null\` in #(
+else case e in #(
+  e) case \`(set -o) 2>/dev/null\` in #(
   *posix*) :
     set -o posix ;; #(
   *) :
      ;;
+esac ;;
 esac
 fi
 "
@@ -185,42 +167,54 @@ as_fn_success || { exitcode=1; echo as_fn_success failed.; }
 as_fn_failure && { exitcode=1; echo as_fn_failure succeeded.; }
 as_fn_ret_success || { exitcode=1; echo as_fn_ret_success failed.; }
 as_fn_ret_failure && { exitcode=1; echo as_fn_ret_failure succeeded.; }
-if ( set x; as_fn_ret_success y && test x = \"\$1\" ); then :
+if ( set x; as_fn_ret_success y && test x = \"\$1\" )
+then :
 
-else
-  exitcode=1; echo positional parameters were not saved.
+else case e in #(
+  e) exitcode=1; echo positional parameters were not saved. ;;
+esac
 fi
 test x\$exitcode = x0 || exit 1
+blah=\$(echo \$(echo blah))
+test x\"\$blah\" = xblah || exit 1
 test -x / || exit 1"
   as_suggested="  as_lineno_1=";as_suggested=$as_suggested$LINENO;as_suggested=$as_suggested" as_lineno_1a=\$LINENO
   as_lineno_2=";as_suggested=$as_suggested$LINENO;as_suggested=$as_suggested" as_lineno_2a=\$LINENO
   eval 'test \"x\$as_lineno_1'\$as_run'\" != \"x\$as_lineno_2'\$as_run'\" &&
-  test \"x\`expr \$as_lineno_1'\$as_run' + 1\`\" = \"x\$as_lineno_2'\$as_run'\"' || exit 1
-test \$(( 1 + 1 )) = 2 || exit 1"
-  if (eval "$as_required") 2>/dev/null; then :
+  test \"x\`expr \$as_lineno_1'\$as_run' + 1\`\" = \"x\$as_lineno_2'\$as_run'\"' || exit 1"
+  if (eval "$as_required") 2>/dev/null
+then :
   as_have_required=yes
-else
-  as_have_required=no
+else case e in #(
+  e) as_have_required=no ;;
+esac
 fi
-  if test x$as_have_required = xyes && (eval "$as_suggested") 2>/dev/null; then :
+  if test x$as_have_required = xyes && (eval "$as_suggested") 2>/dev/null
+then :
 
-else
-  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+else case e in #(
+  e) as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
 as_found=false
 for as_dir in /bin$PATH_SEPARATOR/usr/bin$PATH_SEPARATOR$PATH
 do
   IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
+  case $as_dir in #(((
+    '') as_dir=./ ;;
+    */) ;;
+    *) as_dir=$as_dir/ ;;
+  esac
   as_found=:
   case $as_dir in #(
 	 /*)
 	   for as_base in sh bash ksh sh5; do
 	     # Try only shells that exist, to save several forks.
-	     as_shell=$as_dir/$as_base
+	     as_shell=$as_dir$as_base
 	     if { test -f "$as_shell" || test -f "$as_shell.exe"; } &&
-		    { $as_echo "$as_bourne_compatible""$as_required" | as_run=a "$as_shell"; } 2>/dev/null; then :
+		    as_run=a "$as_shell" -c "$as_bourne_compatible""$as_required" 2>/dev/null
+then :
   CONFIG_SHELL=$as_shell as_have_required=yes
-		   if { $as_echo "$as_bourne_compatible""$as_suggested" | as_run=a "$as_shell"; } 2>/dev/null; then :
+		   if as_run=a "$as_shell" -c "$as_bourne_compatible""$as_suggested" 2>/dev/null
+then :
   break 2
 fi
 fi
@@ -228,14 +222,22 @@ fi
        esac
   as_found=false
 done
-$as_found || { if { test -f "$SHELL" || test -f "$SHELL.exe"; } &&
-	      { $as_echo "$as_bourne_compatible""$as_required" | as_run=a "$SHELL"; } 2>/dev/null; then :
-  CONFIG_SHELL=$SHELL as_have_required=yes
-fi; }
 IFS=$as_save_IFS
+if $as_found
+then :
+
+else case e in #(
+  e) if { test -f "$SHELL" || test -f "$SHELL.exe"; } &&
+	      as_run=a "$SHELL" -c "$as_bourne_compatible""$as_required" 2>/dev/null
+then :
+  CONFIG_SHELL=$SHELL as_have_required=yes
+fi ;;
+esac
+fi
 
 
-      if test "x$CONFIG_SHELL" != x; then :
+      if test "x$CONFIG_SHELL" != x
+then :
   export CONFIG_SHELL
              # We cannot yet assume a decent shell, so we have to provide a
 # neutralization value for shells without unset; and this also
@@ -252,25 +254,27 @@ case $- in # ((((
 esac
 exec $CONFIG_SHELL $as_opts "$as_myself" ${1+"$@"}
 # Admittedly, this is quite paranoid, since all the known shells bail
-# out after a failed `exec'.
-$as_echo "$0: could not re-execute with $CONFIG_SHELL" >&2
+# out after a failed 'exec'.
+printf "%s\n" "$0: could not re-execute with $CONFIG_SHELL" >&2
 exit 255
 fi
 
-    if test x$as_have_required = xno; then :
-  $as_echo "$0: This script requires a shell more modern than all"
-  $as_echo "$0: the shells that I found on your system."
-  if test x${ZSH_VERSION+set} = xset ; then
-    $as_echo "$0: In particular, zsh $ZSH_VERSION has bugs and should"
-    $as_echo "$0: be upgraded to zsh 4.3.4 or later."
+    if test x$as_have_required = xno
+then :
+  printf "%s\n" "$0: This script requires a shell more modern than all"
+  printf "%s\n" "$0: the shells that I found on your system."
+  if test ${ZSH_VERSION+y} ; then
+    printf "%s\n" "$0: In particular, zsh $ZSH_VERSION has bugs and should"
+    printf "%s\n" "$0: be upgraded to zsh 4.3.4 or later."
   else
-    $as_echo "$0: Please tell bug-autoconf@gnu.org about your system,
+    printf "%s\n" "$0: Please tell bug-autoconf@gnu.org about your system,
 $0: including any error possibly output before this
 $0: message. Then install a modern shell, or manually run
 $0: the script under such a shell if you do have one."
   fi
   exit 1
-fi
+fi ;;
+esac
 fi
 fi
 SHELL=${CONFIG_SHELL-/bin/sh}
@@ -291,6 +295,7 @@ as_fn_unset ()
 }
 as_unset=as_fn_unset
 
+
 # as_fn_set_status STATUS
 # -----------------------
 # Set $? to STATUS, without forking.
@@ -322,7 +327,7 @@ as_fn_mkdir_p ()
     as_dirs=
     while :; do
       case $as_dir in #(
-      *\'*) as_qdir=`$as_echo "$as_dir" | sed "s/'/'\\\\\\\\''/g"`;; #'(
+      *\'*) as_qdir=`printf "%s\n" "$as_dir" | sed "s/'/'\\\\\\\\''/g"`;; #'(
       *) as_qdir=$as_dir;;
       esac
       as_dirs="'$as_qdir' $as_dirs"
@@ -331,7 +336,7 @@ $as_expr X"$as_dir" : 'X\(.*[^/]\)//*[^/][^/]*/*$' \| \
 	 X"$as_dir" : 'X\(//\)[^/]' \| \
 	 X"$as_dir" : 'X\(//\)$' \| \
 	 X"$as_dir" : 'X\(/\)' \| . 2>/dev/null ||
-$as_echo X"$as_dir" |
+printf "%s\n" X"$as_dir" |
     sed '/^X\(.*[^/]\)\/\/*[^/][^/]*\/*$/{
 	    s//\1/
 	    q
@@ -370,16 +375,18 @@ as_fn_executable_p ()
 # advantage of any shell optimizations that allow amortized linear growth over
 # repeated appends, instead of the typical quadratic growth present in naive
 # implementations.
-if (eval "as_var=1; as_var+=2; test x\$as_var = x12") 2>/dev/null; then :
+if (eval "as_var=1; as_var+=2; test x\$as_var = x12") 2>/dev/null
+then :
   eval 'as_fn_append ()
   {
     eval $1+=\$2
   }'
-else
-  as_fn_append ()
+else case e in #(
+  e) as_fn_append ()
   {
     eval $1=\$$1\$2
-  }
+  } ;;
+esac
 fi # as_fn_append
 
 # as_fn_arith ARG...
@@ -387,16 +394,18 @@ fi # as_fn_append
 # Perform arithmetic evaluation on the ARGs, and store the result in the
 # global $as_val. Take advantage of shells that can avoid forks. The arguments
 # must be portable across $(()) and expr.
-if (eval "test \$(( 1 + 1 )) = 2") 2>/dev/null; then :
+if (eval "test \$(( 1 + 1 )) = 2") 2>/dev/null
+then :
   eval 'as_fn_arith ()
   {
     as_val=$(( $* ))
   }'
-else
-  as_fn_arith ()
+else case e in #(
+  e) as_fn_arith ()
   {
     as_val=`expr "$@" || test $? -eq 1`
-  }
+  } ;;
+esac
 fi # as_fn_arith
 
 
@@ -410,9 +419,9 @@ as_fn_error ()
   as_status=$1; test $as_status -eq 0 && as_status=1
   if test "$4"; then
     as_lineno=${as_lineno-"$3"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
-    $as_echo "$as_me:${as_lineno-$LINENO}: error: $2" >&$4
+    printf "%s\n" "$as_me:${as_lineno-$LINENO}: error: $2" >&$4
   fi
-  $as_echo "$as_me: error: $2" >&2
+  printf "%s\n" "$as_me: error: $2" >&2
   as_fn_exit $as_status
 } # as_fn_error
 
@@ -439,7 +448,7 @@ as_me=`$as_basename -- "$0" ||
 $as_expr X/"$0" : '.*/\([^/][^/]*\)/*$' \| \
 	 X"$0" : 'X\(//\)$' \| \
 	 X"$0" : 'X\(/\)' \| . 2>/dev/null ||
-$as_echo X/"$0" |
+printf "%s\n" X/"$0" |
     sed '/^.*\/\([^/][^/]*\)\/*$/{
 	    s//\1/
 	    q
@@ -472,6 +481,8 @@ as_cr_alnum=$as_cr_Letters$as_cr_digits
     /[$]LINENO/=
   ' <$as_myself |
     sed '
+      t clear
+      :clear
       s/[$]LINENO.*/&-/
       t lineno
       b
@@ -483,7 +494,7 @@ as_cr_alnum=$as_cr_Letters$as_cr_digits
       s/-\n.*//
     ' >$as_me.lineno &&
   chmod +x "$as_me.lineno" ||
-    { $as_echo "$as_me: error: cannot create $as_me.lineno; rerun with a POSIX shell" >&2; as_fn_exit 1; }
+    { printf "%s\n" "$as_me: error: cannot create $as_me.lineno; rerun with a POSIX shell" >&2; as_fn_exit 1; }
 
   # If we had to re-execute with $CONFIG_SHELL, we're ensured to have
   # already done that, so ensure we don't try to do so again and fall
@@ -497,6 +508,10 @@ as_cr_alnum=$as_cr_Letters$as_cr_digits
   exit
 }
 
+
+# Determine whether it's possible to make 'echo' print without a newline.
+# These variables are no longer used directly by Autoconf, but are AC_SUBSTed
+# for compatibility with existing Makefiles.
 ECHO_C= ECHO_N= ECHO_T=
 case `echo -n x` in #(((((
 -n*)
@@ -510,6 +525,12 @@ case `echo -n x` in #(((((
   ECHO_N='-n';;
 esac
 
+# For backward compatibility with old third-party macros, we provide
+# the shell variables $as_echo and $as_echo_n.  New code should use
+# AS_ECHO(["message"]) and AS_ECHO_N(["message"]), respectively.
+as_echo='printf %s\n'
+as_echo_n='printf %s'
+
 rm -f conf$$ conf$$.exe conf$$.file
 if test -d conf$$.dir; then
   rm -f conf$$.dir/conf$$.file
@@ -521,9 +542,9 @@ if (echo >conf$$.file) 2>/dev/null; then
   if ln -s conf$$.file conf$$ 2>/dev/null; then
     as_ln_s='ln -s'
     # ... but there are two gotchas:
-    # 1) On MSYS, both `ln -s file dir' and `ln file dir' fail.
-    # 2) DJGPP < 2.04 has no symlinks; `ln -s' creates a wrapper executable.
-    # In both cases, we have to default to `cp -pR'.
+    # 1) On MSYS, both 'ln -s file dir' and 'ln file dir' fail.
+    # 2) DJGPP < 2.04 has no symlinks; 'ln -s' creates a wrapper executable.
+    # In both cases, we have to default to 'cp -pR'.
     ln -s conf$$.file conf$$.dir 2>/dev/null && test ! -f conf$$.exe ||
       as_ln_s='cp -pR'
   elif ln conf$$.file conf$$ 2>/dev/null; then
@@ -548,10 +569,12 @@ as_test_x='test -x'
 as_executable_p=as_fn_executable_p
 
 # Sed expression to map a string onto a valid CPP name.
-as_tr_cpp="eval sed 'y%*$as_cr_letters%P$as_cr_LETTERS%;s%[^_$as_cr_alnum]%_%g'"
+as_sed_cpp="y%*$as_cr_letters%P$as_cr_LETTERS%;s%[^_$as_cr_alnum]%_%g"
+as_tr_cpp="eval sed '$as_sed_cpp'" # deprecated
 
 # Sed expression to map a string onto a valid variable name.
-as_tr_sh="eval sed 'y%*+%pp%;s%[^_$as_cr_alnum]%_%g'"
+as_sed_sh="y%*+%pp%;s%[^_$as_cr_alnum]%_%g"
+as_tr_sh="eval sed '$as_sed_sh'" # deprecated
 
 
 test -n "$DJDIR" || exec 7<&0 </dev/null
@@ -584,40 +607,36 @@ PACKAGE_URL=''
 
 # Factoring default headers for most tests.
 ac_includes_default="\
-#include <stdio.h>
-#ifdef HAVE_SYS_TYPES_H
-# include <sys/types.h>
-#endif
-#ifdef HAVE_SYS_STAT_H
-# include <sys/stat.h>
+#include <stddef.h>
+#ifdef HAVE_STDIO_H
+# include <stdio.h>
 #endif
-#ifdef STDC_HEADERS
+#ifdef HAVE_STDLIB_H
 # include <stdlib.h>
-# include <stddef.h>
-#else
-# ifdef HAVE_STDLIB_H
-#  include <stdlib.h>
-# endif
 #endif
 #ifdef HAVE_STRING_H
-# if !defined STDC_HEADERS && defined HAVE_MEMORY_H
-#  include <memory.h>
-# endif
 # include <string.h>
 #endif
-#ifdef HAVE_STRINGS_H
-# include <strings.h>
-#endif
 #ifdef HAVE_INTTYPES_H
 # include <inttypes.h>
 #endif
 #ifdef HAVE_STDINT_H
 # include <stdint.h>
 #endif
+#ifdef HAVE_STRINGS_H
+# include <strings.h>
+#endif
+#ifdef HAVE_SYS_TYPES_H
+# include <sys/types.h>
+#endif
+#ifdef HAVE_SYS_STAT_H
+# include <sys/stat.h>
+#endif
 #ifdef HAVE_UNISTD_H
 # include <unistd.h>
 #endif"
 
+ac_header_cxx_list=
 ac_subst_vars='LTLIBOBJS
 LIBOBJS
 build_dir
@@ -643,9 +662,6 @@ PYBIND11_CFLAGS
 PLUMED_CAN_PYCV
 CYTHON_FOUND
 OPENMP_CXXFLAGS
-EGREP
-GREP
-CXXCPP
 disable_dependency_tracking
 ac_ct_FC
 FCFLAGS
@@ -685,6 +701,7 @@ infodir
 docdir
 oldincludedir
 includedir
+runstatedir
 localstatedir
 sharedstatedir
 sysconfdir
@@ -752,6 +769,7 @@ enable_af_ocl
 enable_af_cuda
 enable_af_cpu
 enable_libtorch
+enable_metatensor
 enable_openmp
 '
       ac_precious_vars='build_alias
@@ -772,8 +790,7 @@ CCC
 CC
 CFLAGS
 FC
-FCFLAGS
-CXXCPP'
+FCFLAGS'
 
 
 # Initialize some variables set by options.
@@ -812,6 +829,7 @@ datadir='${datarootdir}'
 sysconfdir='${prefix}/etc'
 sharedstatedir='${prefix}/com'
 localstatedir='${prefix}/var'
+runstatedir='${localstatedir}/run'
 includedir='${prefix}/include'
 oldincludedir='/usr/include'
 docdir='${datarootdir}/doc/${PACKAGE_TARNAME}'
@@ -841,8 +859,6 @@ do
   *)    ac_optarg=yes ;;
   esac
 
-  # Accept the important Cygnus configure options, so we can diagnose typos.
-
   case $ac_dashdash$ac_option in
   --)
     ac_dashdash=yes ;;
@@ -883,9 +899,9 @@ do
     ac_useropt=`expr "x$ac_option" : 'x-*disable-\(.*\)'`
     # Reject names that are not valid shell variable names.
     expr "x$ac_useropt" : ".*[^-+._$as_cr_alnum]" >/dev/null &&
-      as_fn_error $? "invalid feature name: $ac_useropt"
+      as_fn_error $? "invalid feature name: '$ac_useropt'"
     ac_useropt_orig=$ac_useropt
-    ac_useropt=`$as_echo "$ac_useropt" | sed 's/[-+.]/_/g'`
+    ac_useropt=`printf "%s\n" "$ac_useropt" | sed 's/[-+.]/_/g'`
     case $ac_user_opts in
       *"
 "enable_$ac_useropt"
@@ -909,9 +925,9 @@ do
     ac_useropt=`expr "x$ac_option" : 'x-*enable-\([^=]*\)'`
     # Reject names that are not valid shell variable names.
     expr "x$ac_useropt" : ".*[^-+._$as_cr_alnum]" >/dev/null &&
-      as_fn_error $? "invalid feature name: $ac_useropt"
+      as_fn_error $? "invalid feature name: '$ac_useropt'"
     ac_useropt_orig=$ac_useropt
-    ac_useropt=`$as_echo "$ac_useropt" | sed 's/[-+.]/_/g'`
+    ac_useropt=`printf "%s\n" "$ac_useropt" | sed 's/[-+.]/_/g'`
     case $ac_user_opts in
       *"
 "enable_$ac_useropt"
@@ -1064,6 +1080,15 @@ do
   | -silent | --silent | --silen | --sile | --sil)
     silent=yes ;;
 
+  -runstatedir | --runstatedir | --runstatedi | --runstated \
+  | --runstate | --runstat | --runsta | --runst | --runs \
+  | --run | --ru | --r)
+    ac_prev=runstatedir ;;
+  -runstatedir=* | --runstatedir=* | --runstatedi=* | --runstated=* \
+  | --runstate=* | --runstat=* | --runsta=* | --runst=* | --runs=* \
+  | --run=* | --ru=* | --r=*)
+    runstatedir=$ac_optarg ;;
+
   -sbindir | --sbindir | --sbindi | --sbind | --sbin | --sbi | --sb)
     ac_prev=sbindir ;;
   -sbindir=* | --sbindir=* | --sbindi=* | --sbind=* | --sbin=* \
@@ -1113,9 +1138,9 @@ do
     ac_useropt=`expr "x$ac_option" : 'x-*with-\([^=]*\)'`
     # Reject names that are not valid shell variable names.
     expr "x$ac_useropt" : ".*[^-+._$as_cr_alnum]" >/dev/null &&
-      as_fn_error $? "invalid package name: $ac_useropt"
+      as_fn_error $? "invalid package name: '$ac_useropt'"
     ac_useropt_orig=$ac_useropt
-    ac_useropt=`$as_echo "$ac_useropt" | sed 's/[-+.]/_/g'`
+    ac_useropt=`printf "%s\n" "$ac_useropt" | sed 's/[-+.]/_/g'`
     case $ac_user_opts in
       *"
 "with_$ac_useropt"
@@ -1129,9 +1154,9 @@ do
     ac_useropt=`expr "x$ac_option" : 'x-*without-\(.*\)'`
     # Reject names that are not valid shell variable names.
     expr "x$ac_useropt" : ".*[^-+._$as_cr_alnum]" >/dev/null &&
-      as_fn_error $? "invalid package name: $ac_useropt"
+      as_fn_error $? "invalid package name: '$ac_useropt'"
     ac_useropt_orig=$ac_useropt
-    ac_useropt=`$as_echo "$ac_useropt" | sed 's/[-+.]/_/g'`
+    ac_useropt=`printf "%s\n" "$ac_useropt" | sed 's/[-+.]/_/g'`
     case $ac_user_opts in
       *"
 "with_$ac_useropt"
@@ -1159,8 +1184,8 @@ do
   | --x-librar=* | --x-libra=* | --x-libr=* | --x-lib=* | --x-li=* | --x-l=*)
     x_libraries=$ac_optarg ;;
 
-  -*) as_fn_error $? "unrecognized option: \`$ac_option'
-Try \`$0 --help' for more information"
+  -*) as_fn_error $? "unrecognized option: '$ac_option'
+Try '$0 --help' for more information"
     ;;
 
   *=*)
@@ -1168,16 +1193,16 @@ Try \`$0 --help' for more information"
     # Reject names that are not valid shell variable names.
     case $ac_envvar in #(
       '' | [0-9]* | *[!_$as_cr_alnum]* )
-      as_fn_error $? "invalid variable name: \`$ac_envvar'" ;;
+      as_fn_error $? "invalid variable name: '$ac_envvar'" ;;
     esac
     eval $ac_envvar=\$ac_optarg
     export $ac_envvar ;;
 
   *)
     # FIXME: should be removed in autoconf 3.0.
-    $as_echo "$as_me: WARNING: you should use --build, --host, --target" >&2
+    printf "%s\n" "$as_me: WARNING: you should use --build, --host, --target" >&2
     expr "x$ac_option" : ".*[^-._$as_cr_alnum]" >/dev/null &&
-      $as_echo "$as_me: WARNING: invalid host type: $ac_option" >&2
+      printf "%s\n" "$as_me: WARNING: invalid host type: $ac_option" >&2
     : "${build_alias=$ac_option} ${host_alias=$ac_option} ${target_alias=$ac_option}"
     ;;
 
@@ -1193,7 +1218,7 @@ if test -n "$ac_unrecognized_opts"; then
   case $enable_option_checking in
     no) ;;
     fatal) as_fn_error $? "unrecognized options: $ac_unrecognized_opts" ;;
-    *)     $as_echo "$as_me: WARNING: unrecognized options: $ac_unrecognized_opts" >&2 ;;
+    *)     printf "%s\n" "$as_me: WARNING: unrecognized options: $ac_unrecognized_opts" >&2 ;;
   esac
 fi
 
@@ -1201,7 +1226,7 @@ fi
 for ac_var in	exec_prefix prefix bindir sbindir libexecdir datarootdir \
 		datadir sysconfdir sharedstatedir localstatedir includedir \
 		oldincludedir docdir infodir htmldir dvidir pdfdir psdir \
-		libdir localedir mandir
+		libdir localedir mandir runstatedir
 do
   eval ac_val=\$$ac_var
   # Remove trailing slashes.
@@ -1218,7 +1243,7 @@ do
   as_fn_error $? "expected an absolute directory name for --$ac_var: $ac_val"
 done
 
-# There might be people who depend on the old broken behavior: `$host'
+# There might be people who depend on the old broken behavior: '$host'
 # used to hold the argument of --host etc.
 # FIXME: To remove some day.
 build=$build_alias
@@ -1257,7 +1282,7 @@ $as_expr X"$as_myself" : 'X\(.*[^/]\)//*[^/][^/]*/*$' \| \
 	 X"$as_myself" : 'X\(//\)[^/]' \| \
 	 X"$as_myself" : 'X\(//\)$' \| \
 	 X"$as_myself" : 'X\(/\)' \| . 2>/dev/null ||
-$as_echo X"$as_myself" |
+printf "%s\n" X"$as_myself" |
     sed '/^X\(.*[^/]\)\/\/*[^/][^/]*\/*$/{
 	    s//\1/
 	    q
@@ -1286,7 +1311,7 @@ if test ! -r "$srcdir/$ac_unique_file"; then
   test "$ac_srcdir_defaulted" = yes && srcdir="$ac_confdir or .."
   as_fn_error $? "cannot find sources ($ac_unique_file) in $srcdir"
 fi
-ac_msg="sources are in $srcdir, but \`cd $srcdir' does not work"
+ac_msg="sources are in $srcdir, but 'cd $srcdir' does not work"
 ac_abs_confdir=`(
 	cd "$srcdir" && test -r "./$ac_unique_file" || as_fn_error $? "$ac_msg"
 	pwd)`
@@ -1314,7 +1339,7 @@ if test "$ac_init_help" = "long"; then
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<_ACEOF
-\`configure' configures PLUMED 2 to adapt to many kinds of systems.
+'configure' configures PLUMED 2 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1328,11 +1353,11 @@ Configuration:
       --help=short        display options specific to this package
       --help=recursive    display the short help of all the included packages
   -V, --version           display version information and exit
-  -q, --quiet, --silent   do not print \`checking ...' messages
+  -q, --quiet, --silent   do not print 'checking ...' messages
       --cache-file=FILE   cache test results in FILE [disabled]
-  -C, --config-cache      alias for \`--cache-file=config.cache'
+  -C, --config-cache      alias for '--cache-file=config.cache'
   -n, --no-create         do not create output files
-      --srcdir=DIR        find the sources in DIR [configure dir or \`..']
+      --srcdir=DIR        find the sources in DIR [configure dir or '..']
 
 Installation directories:
   --prefix=PREFIX         install architecture-independent files in PREFIX
@@ -1340,10 +1365,10 @@ Installation directories:
   --exec-prefix=EPREFIX   install architecture-dependent files in EPREFIX
                           [PREFIX]
 
-By default, \`make install' will install all the files in
-\`$ac_default_prefix/bin', \`$ac_default_prefix/lib' etc.  You can specify
-an installation prefix other than \`$ac_default_prefix' using \`--prefix',
-for instance \`--prefix=\$HOME'.
+By default, 'make install' will install all the files in
+'$ac_default_prefix/bin', '$ac_default_prefix/lib' etc.  You can specify
+an installation prefix other than '$ac_default_prefix' using '--prefix',
+for instance '--prefix=\$HOME'.
 
 For better control, use the options below.
 
@@ -1354,6 +1379,7 @@ Fine tuning of the installation directories:
   --sysconfdir=DIR        read-only single-machine data [PREFIX/etc]
   --sharedstatedir=DIR    modifiable architecture-independent data [PREFIX/com]
   --localstatedir=DIR     modifiable single-machine data [PREFIX/var]
+  --runstatedir=DIR       modifiable per-process data [LOCALSTATEDIR/run]
   --libdir=DIR            object code libraries [EPREFIX/lib]
   --includedir=DIR        C header files [PREFIX/include]
   --oldincludedir=DIR     C header files for non-gcc [/usr/include]
@@ -1454,6 +1480,7 @@ Optional Features:
   --enable-af_cuda        enable search for arrayfire_cuda, default: no
   --enable-af_cpu         enable search for arrayfire_cpu, default: no
   --enable-libtorch       enable search for libtorch, default: no
+  --enable-metatensor     enable search for metatensor, default: no
   --disable-openmp        do not use OpenMP
 
 Some influential environment variables:
@@ -1481,9 +1508,8 @@ Some influential environment variables:
   CFLAGS      C compiler flags
   FC          Fortran compiler command
   FCFLAGS     Fortran compiler flags
-  CXXCPP      C++ preprocessor
 
-Use these variables to override the choices made by `configure' or to help
+Use these variables to override the choices made by 'configure' or to help
 it to find libraries and programs with nonstandard names/locations.
 
 Report bugs to the package provider.
@@ -1502,9 +1528,9 @@ if test "$ac_init_help" = "recursive"; then
 case "$ac_dir" in
 .) ac_dir_suffix= ac_top_builddir_sub=. ac_top_build_prefix= ;;
 *)
-  ac_dir_suffix=/`$as_echo "$ac_dir" | sed 's|^\.[\\/]||'`
+  ac_dir_suffix=/`printf "%s\n" "$ac_dir" | sed 's|^\.[\\/]||'`
   # A ".." for each directory in $ac_dir_suffix.
-  ac_top_builddir_sub=`$as_echo "$ac_dir_suffix" | sed 's|/[^\\/]*|/..|g;s|/||'`
+  ac_top_builddir_sub=`printf "%s\n" "$ac_dir_suffix" | sed 's|/[^\\/]*|/..|g;s|/||'`
   case $ac_top_builddir_sub in
   "") ac_top_builddir_sub=. ac_top_build_prefix= ;;
   *)  ac_top_build_prefix=$ac_top_builddir_sub/ ;;
@@ -1532,7 +1558,8 @@ esac
 ac_abs_srcdir=$ac_abs_top_srcdir$ac_dir_suffix
 
     cd "$ac_dir" || { ac_status=$?; continue; }
-    # Check for guested configure.
+    # Check for configure.gnu first; this name is used for a wrapper for
+    # Metaconfig's "Configure" on case-insensitive file systems.
     if test -f "$ac_srcdir/configure.gnu"; then
       echo &&
       $SHELL "$ac_srcdir/configure.gnu" --help=recursive
@@ -1540,7 +1567,7 @@ ac_abs_srcdir=$ac_abs_top_srcdir$ac_dir_suffix
       echo &&
       $SHELL "$ac_srcdir/configure" --help=recursive
     else
-      $as_echo "$as_me: WARNING: no configuration information is in $ac_dir" >&2
+      printf "%s\n" "$as_me: WARNING: no configuration information is in $ac_dir" >&2
     fi || ac_status=$?
     cd "$ac_pwd" || { ac_status=$?; break; }
   done
@@ -1550,9 +1577,9 @@ test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
 PLUMED configure 2
-generated by GNU Autoconf 2.69
+generated by GNU Autoconf 2.72
 
-Copyright (C) 2012 Free Software Foundation, Inc.
+Copyright (C) 2023 Free Software Foundation, Inc.
 This configure script is free software; the Free Software Foundation
 gives unlimited permission to copy, distribute and modify it.
 _ACEOF
@@ -1569,14 +1596,14 @@ fi
 ac_fn_cxx_try_compile ()
 {
   as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
-  rm -f conftest.$ac_objext
+  rm -f conftest.$ac_objext conftest.beam
   if { { ac_try="$ac_compile"
 case "(($ac_try" in
   *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
   *) ac_try_echo=$ac_try;;
 esac
 eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
-$as_echo "$ac_try_echo"; } >&5
+printf "%s\n" "$ac_try_echo"; } >&5
   (eval "$ac_compile") 2>conftest.err
   ac_status=$?
   if test -s conftest.err; then
@@ -1584,17 +1611,19 @@ $as_echo "$ac_try_echo"; } >&5
     cat conftest.er1 >&5
     mv -f conftest.er1 conftest.err
   fi
-  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
   test $ac_status = 0; } && {
 	 test -z "$ac_cxx_werror_flag" ||
 	 test ! -s conftest.err
-       } && test -s conftest.$ac_objext; then :
+       } && test -s conftest.$ac_objext
+then :
   ac_retval=0
-else
-  $as_echo "$as_me: failed program was:" >&5
+else case e in #(
+  e) printf "%s\n" "$as_me: failed program was:" >&5
 sed 's/^/| /' conftest.$ac_ext >&5
 
-	ac_retval=1
+	ac_retval=1 ;;
+esac
 fi
   eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
   as_fn_set_status $ac_retval
@@ -1607,14 +1636,14 @@ fi
 ac_fn_c_try_compile ()
 {
   as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
-  rm -f conftest.$ac_objext
+  rm -f conftest.$ac_objext conftest.beam
   if { { ac_try="$ac_compile"
 case "(($ac_try" in
   *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
   *) ac_try_echo=$ac_try;;
 esac
 eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
-$as_echo "$ac_try_echo"; } >&5
+printf "%s\n" "$ac_try_echo"; } >&5
   (eval "$ac_compile") 2>conftest.err
   ac_status=$?
   if test -s conftest.err; then
@@ -1622,17 +1651,19 @@ $as_echo "$ac_try_echo"; } >&5
     cat conftest.er1 >&5
     mv -f conftest.er1 conftest.err
   fi
-  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
   test $ac_status = 0; } && {
 	 test -z "$ac_c_werror_flag" ||
 	 test ! -s conftest.err
-       } && test -s conftest.$ac_objext; then :
+       } && test -s conftest.$ac_objext
+then :
   ac_retval=0
-else
-  $as_echo "$as_me: failed program was:" >&5
+else case e in #(
+  e) printf "%s\n" "$as_me: failed program was:" >&5
 sed 's/^/| /' conftest.$ac_ext >&5
 
-	ac_retval=1
+	ac_retval=1 ;;
+esac
 fi
   eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
   as_fn_set_status $ac_retval
@@ -1645,14 +1676,14 @@ fi
 ac_fn_fc_try_compile ()
 {
   as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
-  rm -f conftest.$ac_objext
+  rm -f conftest.$ac_objext conftest.beam
   if { { ac_try="$ac_compile"
 case "(($ac_try" in
   *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
   *) ac_try_echo=$ac_try;;
 esac
 eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
-$as_echo "$ac_try_echo"; } >&5
+printf "%s\n" "$ac_try_echo"; } >&5
   (eval "$ac_compile") 2>conftest.err
   ac_status=$?
   if test -s conftest.err; then
@@ -1660,17 +1691,19 @@ $as_echo "$ac_try_echo"; } >&5
     cat conftest.er1 >&5
     mv -f conftest.er1 conftest.err
   fi
-  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
   test $ac_status = 0; } && {
 	 test -z "$ac_fc_werror_flag" ||
 	 test ! -s conftest.err
-       } && test -s conftest.$ac_objext; then :
+       } && test -s conftest.$ac_objext
+then :
   ac_retval=0
-else
-  $as_echo "$as_me: failed program was:" >&5
+else case e in #(
+  e) printf "%s\n" "$as_me: failed program was:" >&5
 sed 's/^/| /' conftest.$ac_ext >&5
 
-	ac_retval=1
+	ac_retval=1 ;;
+esac
 fi
   eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
   as_fn_set_status $ac_retval
@@ -1683,14 +1716,14 @@ fi
 ac_fn_cxx_try_link ()
 {
   as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
-  rm -f conftest.$ac_objext conftest$ac_exeext
+  rm -f conftest.$ac_objext conftest.beam conftest$ac_exeext
   if { { ac_try="$ac_link"
 case "(($ac_try" in
   *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
   *) ac_try_echo=$ac_try;;
 esac
 eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
-$as_echo "$ac_try_echo"; } >&5
+printf "%s\n" "$ac_try_echo"; } >&5
   (eval "$ac_link") 2>conftest.err
   ac_status=$?
   if test -s conftest.err; then
@@ -1698,20 +1731,22 @@ $as_echo "$ac_try_echo"; } >&5
     cat conftest.er1 >&5
     mv -f conftest.er1 conftest.err
   fi
-  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
   test $ac_status = 0; } && {
 	 test -z "$ac_cxx_werror_flag" ||
 	 test ! -s conftest.err
        } && test -s conftest$ac_exeext && {
 	 test "$cross_compiling" = yes ||
 	 test -x conftest$ac_exeext
-       }; then :
+       }
+then :
   ac_retval=0
-else
-  $as_echo "$as_me: failed program was:" >&5
+else case e in #(
+  e) printf "%s\n" "$as_me: failed program was:" >&5
 sed 's/^/| /' conftest.$ac_ext >&5
 
-	ac_retval=1
+	ac_retval=1 ;;
+esac
 fi
   # Delete the IPA/IPO (Inter Procedural Analysis/Optimization) information
   # created by the PGI compiler (conftest_ipa8_conftest.oo), as it would
@@ -1729,14 +1764,14 @@ fi
 ac_fn_c_try_link ()
 {
   as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
-  rm -f conftest.$ac_objext conftest$ac_exeext
+  rm -f conftest.$ac_objext conftest.beam conftest$ac_exeext
   if { { ac_try="$ac_link"
 case "(($ac_try" in
   *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
   *) ac_try_echo=$ac_try;;
 esac
 eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
-$as_echo "$ac_try_echo"; } >&5
+printf "%s\n" "$ac_try_echo"; } >&5
   (eval "$ac_link") 2>conftest.err
   ac_status=$?
   if test -s conftest.err; then
@@ -1744,20 +1779,22 @@ $as_echo "$ac_try_echo"; } >&5
     cat conftest.er1 >&5
     mv -f conftest.er1 conftest.err
   fi
-  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
   test $ac_status = 0; } && {
 	 test -z "$ac_c_werror_flag" ||
 	 test ! -s conftest.err
        } && test -s conftest$ac_exeext && {
 	 test "$cross_compiling" = yes ||
 	 test -x conftest$ac_exeext
-       }; then :
+       }
+then :
   ac_retval=0
-else
-  $as_echo "$as_me: failed program was:" >&5
+else case e in #(
+  e) printf "%s\n" "$as_me: failed program was:" >&5
 sed 's/^/| /' conftest.$ac_ext >&5
 
-	ac_retval=1
+	ac_retval=1 ;;
+esac
 fi
   # Delete the IPA/IPO (Inter Procedural Analysis/Optimization) information
   # created by the PGI compiler (conftest_ipa8_conftest.oo), as it would
@@ -1771,8 +1808,8 @@ fi
 
 # ac_fn_cxx_try_run LINENO
 # ------------------------
-# Try to link conftest.$ac_ext, and return whether this succeeded. Assumes
-# that executables *can* be run.
+# Try to run conftest.$ac_ext, and return whether this succeeded. Assumes that
+# executables *can* be run.
 ac_fn_cxx_try_run ()
 {
   as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
@@ -1782,28 +1819,30 @@ case "(($ac_try" in
   *) ac_try_echo=$ac_try;;
 esac
 eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
-$as_echo "$ac_try_echo"; } >&5
+printf "%s\n" "$ac_try_echo"; } >&5
   (eval "$ac_link") 2>&5
   ac_status=$?
-  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
   test $ac_status = 0; } && { ac_try='./conftest$ac_exeext'
   { { case "(($ac_try" in
   *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
   *) ac_try_echo=$ac_try;;
 esac
 eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
-$as_echo "$ac_try_echo"; } >&5
+printf "%s\n" "$ac_try_echo"; } >&5
   (eval "$ac_try") 2>&5
   ac_status=$?
-  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
-  test $ac_status = 0; }; }; then :
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }
+then :
   ac_retval=0
-else
-  $as_echo "$as_me: program exited with status $ac_status" >&5
-       $as_echo "$as_me: failed program was:" >&5
+else case e in #(
+  e) printf "%s\n" "$as_me: program exited with status $ac_status" >&5
+       printf "%s\n" "$as_me: failed program was:" >&5
 sed 's/^/| /' conftest.$ac_ext >&5
 
-       ac_retval=$ac_status
+       ac_retval=$ac_status ;;
+esac
 fi
   rm -rf conftest.dSYM conftest_ipa8_conftest.oo
   eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
@@ -1811,130 +1850,6 @@ fi
 
 } # ac_fn_cxx_try_run
 
-# ac_fn_cxx_try_cpp LINENO
-# ------------------------
-# Try to preprocess conftest.$ac_ext, and return whether this succeeded.
-ac_fn_cxx_try_cpp ()
-{
-  as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
-  if { { ac_try="$ac_cpp conftest.$ac_ext"
-case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
-$as_echo "$ac_try_echo"; } >&5
-  (eval "$ac_cpp conftest.$ac_ext") 2>conftest.err
-  ac_status=$?
-  if test -s conftest.err; then
-    grep -v '^ *+' conftest.err >conftest.er1
-    cat conftest.er1 >&5
-    mv -f conftest.er1 conftest.err
-  fi
-  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
-  test $ac_status = 0; } > conftest.i && {
-	 test -z "$ac_cxx_preproc_warn_flag$ac_cxx_werror_flag" ||
-	 test ! -s conftest.err
-       }; then :
-  ac_retval=0
-else
-  $as_echo "$as_me: failed program was:" >&5
-sed 's/^/| /' conftest.$ac_ext >&5
-
-    ac_retval=1
-fi
-  eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
-  as_fn_set_status $ac_retval
-
-} # ac_fn_cxx_try_cpp
-
-# ac_fn_cxx_check_header_mongrel LINENO HEADER VAR INCLUDES
-# ---------------------------------------------------------
-# Tests whether HEADER exists, giving a warning if it cannot be compiled using
-# the include files in INCLUDES and setting the cache variable VAR
-# accordingly.
-ac_fn_cxx_check_header_mongrel ()
-{
-  as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
-  if eval \${$3+:} false; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for $2" >&5
-$as_echo_n "checking for $2... " >&6; }
-if eval \${$3+:} false; then :
-  $as_echo_n "(cached) " >&6
-fi
-eval ac_res=\$$3
-	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
-$as_echo "$ac_res" >&6; }
-else
-  # Is the header compilable?
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking $2 usability" >&5
-$as_echo_n "checking $2 usability... " >&6; }
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-$4
-#include <$2>
-_ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
-  ac_header_compiler=yes
-else
-  ac_header_compiler=no
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_header_compiler" >&5
-$as_echo "$ac_header_compiler" >&6; }
-
-# Is the header present?
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking $2 presence" >&5
-$as_echo_n "checking $2 presence... " >&6; }
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#include <$2>
-_ACEOF
-if ac_fn_cxx_try_cpp "$LINENO"; then :
-  ac_header_preproc=yes
-else
-  ac_header_preproc=no
-fi
-rm -f conftest.err conftest.i conftest.$ac_ext
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_header_preproc" >&5
-$as_echo "$ac_header_preproc" >&6; }
-
-# So?  What about this header?
-case $ac_header_compiler:$ac_header_preproc:$ac_cxx_preproc_warn_flag in #((
-  yes:no: )
-    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: $2: accepted by the compiler, rejected by the preprocessor!" >&5
-$as_echo "$as_me: WARNING: $2: accepted by the compiler, rejected by the preprocessor!" >&2;}
-    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: $2: proceeding with the compiler's result" >&5
-$as_echo "$as_me: WARNING: $2: proceeding with the compiler's result" >&2;}
-    ;;
-  no:yes:* )
-    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: $2: present but cannot be compiled" >&5
-$as_echo "$as_me: WARNING: $2: present but cannot be compiled" >&2;}
-    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: $2:     check for missing prerequisite headers?" >&5
-$as_echo "$as_me: WARNING: $2:     check for missing prerequisite headers?" >&2;}
-    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: $2: see the Autoconf documentation" >&5
-$as_echo "$as_me: WARNING: $2: see the Autoconf documentation" >&2;}
-    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: $2:     section \"Present But Cannot Be Compiled\"" >&5
-$as_echo "$as_me: WARNING: $2:     section \"Present But Cannot Be Compiled\"" >&2;}
-    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: $2: proceeding with the compiler's result" >&5
-$as_echo "$as_me: WARNING: $2: proceeding with the compiler's result" >&2;}
-    ;;
-esac
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for $2" >&5
-$as_echo_n "checking for $2... " >&6; }
-if eval \${$3+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  eval "$3=\$ac_header_compiler"
-fi
-eval ac_res=\$$3
-	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
-$as_echo "$ac_res" >&6; }
-fi
-  eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
-
-} # ac_fn_cxx_check_header_mongrel
-
 # ac_fn_cxx_check_header_compile LINENO HEADER VAR INCLUDES
 # ---------------------------------------------------------
 # Tests whether HEADER exists and can be compiled using the include files in
@@ -1942,37 +1857,61 @@ fi
 ac_fn_cxx_check_header_compile ()
 {
   as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for $2" >&5
-$as_echo_n "checking for $2... " >&6; }
-if eval \${$3+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $2" >&5
+printf %s "checking for $2... " >&6; }
+if eval test \${$3+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 $4
 #include <$2>
 _ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"
+then :
   eval "$3=yes"
-else
-  eval "$3=no"
+else case e in #(
+  e) eval "$3=no" ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext ;;
+esac
 fi
 eval ac_res=\$$3
-	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
-$as_echo "$ac_res" >&6; }
+	       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+printf "%s\n" "$ac_res" >&6; }
   eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
 
 } # ac_fn_cxx_check_header_compile
+ac_configure_args_raw=
+for ac_arg
+do
+  case $ac_arg in
+  *\'*)
+    ac_arg=`printf "%s\n" "$ac_arg" | sed "s/'/'\\\\\\\\''/g"` ;;
+  esac
+  as_fn_append ac_configure_args_raw " '$ac_arg'"
+done
+
+case $ac_configure_args_raw in
+  *$as_nl*)
+    ac_safe_unquote= ;;
+  *)
+    ac_unsafe_z='|&;<>()$`\\"*?[ ''	' # This string ends in space, tab.
+    ac_unsafe_a="$ac_unsafe_z#~"
+    ac_safe_unquote="s/ '\\([^$ac_unsafe_a][^$ac_unsafe_z]*\\)'/ \\1/g"
+    ac_configure_args_raw=`      printf "%s\n" "$ac_configure_args_raw" | sed "$ac_safe_unquote"`;;
+esac
+
 cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
 It was created by PLUMED $as_me 2, which was
-generated by GNU Autoconf 2.69.  Invocation command line was
+generated by GNU Autoconf 2.72.  Invocation command line was
 
-  $ $0 $@
+  $ $0$ac_configure_args_raw
 
 _ACEOF
 exec 5>>config.log
@@ -2005,8 +1944,12 @@ as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
 for as_dir in $PATH
 do
   IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
-    $as_echo "PATH: $as_dir"
+  case $as_dir in #(((
+    '') as_dir=./ ;;
+    */) ;;
+    *) as_dir=$as_dir/ ;;
+  esac
+    printf "%s\n" "PATH: $as_dir"
   done
 IFS=$as_save_IFS
 
@@ -2041,7 +1984,7 @@ do
     | -silent | --silent | --silen | --sile | --sil)
       continue ;;
     *\'*)
-      ac_arg=`$as_echo "$ac_arg" | sed "s/'/'\\\\\\\\''/g"` ;;
+      ac_arg=`printf "%s\n" "$ac_arg" | sed "s/'/'\\\\\\\\''/g"` ;;
     esac
     case $ac_pass in
     1) as_fn_append ac_configure_args0 " '$ac_arg'" ;;
@@ -2076,11 +2019,13 @@ done
 # WARNING: Use '\'' to represent an apostrophe within the trap.
 # WARNING: Do not start the trap code with a newline, due to a FreeBSD 4.0 bug.
 trap 'exit_status=$?
+  # Sanitize IFS.
+  IFS=" ""	$as_nl"
   # Save into config.log some information that might help in debugging.
   {
     echo
 
-    $as_echo "## ---------------- ##
+    printf "%s\n" "## ---------------- ##
 ## Cache variables. ##
 ## ---------------- ##"
     echo
@@ -2091,8 +2036,8 @@ trap 'exit_status=$?
     case $ac_val in #(
     *${as_nl}*)
       case $ac_var in #(
-      *_cv_*) { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cache variable $ac_var contains a newline" >&5
-$as_echo "$as_me: WARNING: cache variable $ac_var contains a newline" >&2;} ;;
+      *_cv_*) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cache variable $ac_var contains a newline" >&5
+printf "%s\n" "$as_me: WARNING: cache variable $ac_var contains a newline" >&2;} ;;
       esac
       case $ac_var in #(
       _ | IFS | as_nl) ;; #(
@@ -2116,7 +2061,7 @@ $as_echo "$as_me: WARNING: cache variable $ac_var contains a newline" >&2;} ;;
 )
     echo
 
-    $as_echo "## ----------------- ##
+    printf "%s\n" "## ----------------- ##
 ## Output variables. ##
 ## ----------------- ##"
     echo
@@ -2124,14 +2069,14 @@ $as_echo "$as_me: WARNING: cache variable $ac_var contains a newline" >&2;} ;;
     do
       eval ac_val=\$$ac_var
       case $ac_val in
-      *\'\''*) ac_val=`$as_echo "$ac_val" | sed "s/'\''/'\''\\\\\\\\'\'''\''/g"`;;
+      *\'\''*) ac_val=`printf "%s\n" "$ac_val" | sed "s/'\''/'\''\\\\\\\\'\'''\''/g"`;;
       esac
-      $as_echo "$ac_var='\''$ac_val'\''"
+      printf "%s\n" "$ac_var='\''$ac_val'\''"
     done | sort
     echo
 
     if test -n "$ac_subst_files"; then
-      $as_echo "## ------------------- ##
+      printf "%s\n" "## ------------------- ##
 ## File substitutions. ##
 ## ------------------- ##"
       echo
@@ -2139,15 +2084,15 @@ $as_echo "$as_me: WARNING: cache variable $ac_var contains a newline" >&2;} ;;
       do
 	eval ac_val=\$$ac_var
 	case $ac_val in
-	*\'\''*) ac_val=`$as_echo "$ac_val" | sed "s/'\''/'\''\\\\\\\\'\'''\''/g"`;;
+	*\'\''*) ac_val=`printf "%s\n" "$ac_val" | sed "s/'\''/'\''\\\\\\\\'\'''\''/g"`;;
 	esac
-	$as_echo "$ac_var='\''$ac_val'\''"
+	printf "%s\n" "$ac_var='\''$ac_val'\''"
       done | sort
       echo
     fi
 
     if test -s confdefs.h; then
-      $as_echo "## ----------- ##
+      printf "%s\n" "## ----------- ##
 ## confdefs.h. ##
 ## ----------- ##"
       echo
@@ -2155,8 +2100,8 @@ $as_echo "$as_me: WARNING: cache variable $ac_var contains a newline" >&2;} ;;
       echo
     fi
     test "$ac_signal" != 0 &&
-      $as_echo "$as_me: caught signal $ac_signal"
-    $as_echo "$as_me: exit $exit_status"
+      printf "%s\n" "$as_me: caught signal $ac_signal"
+    printf "%s\n" "$as_me: exit $exit_status"
   } >&5
   rm -f core *.core core.conftest.* &&
     rm -f -r conftest* confdefs* conf$$* $ac_clean_files &&
@@ -2170,65 +2115,50 @@ ac_signal=0
 # confdefs.h avoids OS command line length limits that DEFS can exceed.
 rm -f -r conftest* confdefs.h
 
-$as_echo "/* confdefs.h */" > confdefs.h
+printf "%s\n" "/* confdefs.h */" > confdefs.h
 
 # Predefined preprocessor variables.
 
-cat >>confdefs.h <<_ACEOF
-#define PACKAGE_NAME "$PACKAGE_NAME"
-_ACEOF
+printf "%s\n" "#define PACKAGE_NAME \"$PACKAGE_NAME\"" >>confdefs.h
 
-cat >>confdefs.h <<_ACEOF
-#define PACKAGE_TARNAME "$PACKAGE_TARNAME"
-_ACEOF
+printf "%s\n" "#define PACKAGE_TARNAME \"$PACKAGE_TARNAME\"" >>confdefs.h
 
-cat >>confdefs.h <<_ACEOF
-#define PACKAGE_VERSION "$PACKAGE_VERSION"
-_ACEOF
+printf "%s\n" "#define PACKAGE_VERSION \"$PACKAGE_VERSION\"" >>confdefs.h
 
-cat >>confdefs.h <<_ACEOF
-#define PACKAGE_STRING "$PACKAGE_STRING"
-_ACEOF
+printf "%s\n" "#define PACKAGE_STRING \"$PACKAGE_STRING\"" >>confdefs.h
 
-cat >>confdefs.h <<_ACEOF
-#define PACKAGE_BUGREPORT "$PACKAGE_BUGREPORT"
-_ACEOF
+printf "%s\n" "#define PACKAGE_BUGREPORT \"$PACKAGE_BUGREPORT\"" >>confdefs.h
 
-cat >>confdefs.h <<_ACEOF
-#define PACKAGE_URL "$PACKAGE_URL"
-_ACEOF
+printf "%s\n" "#define PACKAGE_URL \"$PACKAGE_URL\"" >>confdefs.h
 
 
 # Let the site file select an alternate cache file if it wants to.
 # Prefer an explicitly selected file to automatically selected ones.
-ac_site_file1=NONE
-ac_site_file2=NONE
 if test -n "$CONFIG_SITE"; then
-  # We do not want a PATH search for config.site.
-  case $CONFIG_SITE in #((
-    -*)  ac_site_file1=./$CONFIG_SITE;;
-    */*) ac_site_file1=$CONFIG_SITE;;
-    *)   ac_site_file1=./$CONFIG_SITE;;
-  esac
+  ac_site_files="$CONFIG_SITE"
 elif test "x$prefix" != xNONE; then
-  ac_site_file1=$prefix/share/config.site
-  ac_site_file2=$prefix/etc/config.site
+  ac_site_files="$prefix/share/config.site $prefix/etc/config.site"
 else
-  ac_site_file1=$ac_default_prefix/share/config.site
-  ac_site_file2=$ac_default_prefix/etc/config.site
+  ac_site_files="$ac_default_prefix/share/config.site $ac_default_prefix/etc/config.site"
 fi
-for ac_site_file in "$ac_site_file1" "$ac_site_file2"
+
+for ac_site_file in $ac_site_files
 do
-  test "x$ac_site_file" = xNONE && continue
-  if test /dev/null != "$ac_site_file" && test -r "$ac_site_file"; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: loading site script $ac_site_file" >&5
-$as_echo "$as_me: loading site script $ac_site_file" >&6;}
+  case $ac_site_file in #(
+  */*) :
+     ;; #(
+  *) :
+    ac_site_file=./$ac_site_file ;;
+esac
+  if test -f "$ac_site_file" && test -r "$ac_site_file"; then
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: loading site script $ac_site_file" >&5
+printf "%s\n" "$as_me: loading site script $ac_site_file" >&6;}
     sed 's/^/| /' "$ac_site_file" >&5
     . "$ac_site_file" \
-      || { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
-$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+      || { { printf "%s\n" "$as_me:${as_lineno-$LINENO}: error: in '$ac_pwd':" >&5
+printf "%s\n" "$as_me: error: in '$ac_pwd':" >&2;}
 as_fn_error $? "failed to load site script $ac_site_file
-See \`config.log' for more details" "$LINENO" 5; }
+See 'config.log' for more details" "$LINENO" 5; }
   fi
 done
 
@@ -2236,121 +2166,672 @@ if test -r "$cache_file"; then
   # Some versions of bash will fail to source /dev/null (special files
   # actually), so we avoid doing that.  DJGPP emulates it as a regular file.
   if test /dev/null != "$cache_file" && test -f "$cache_file"; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: loading cache $cache_file" >&5
-$as_echo "$as_me: loading cache $cache_file" >&6;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: loading cache $cache_file" >&5
+printf "%s\n" "$as_me: loading cache $cache_file" >&6;}
     case $cache_file in
       [\\/]* | ?:[\\/]* ) . "$cache_file";;
       *)                      . "./$cache_file";;
     esac
   fi
 else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: creating cache $cache_file" >&5
-$as_echo "$as_me: creating cache $cache_file" >&6;}
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: creating cache $cache_file" >&5
+printf "%s\n" "$as_me: creating cache $cache_file" >&6;}
   >$cache_file
 fi
 
-# Check that the precious variables saved in the cache have kept the same
-# value.
-ac_cache_corrupted=false
-for ac_var in $ac_precious_vars; do
-  eval ac_old_set=\$ac_cv_env_${ac_var}_set
-  eval ac_new_set=\$ac_env_${ac_var}_set
-  eval ac_old_val=\$ac_cv_env_${ac_var}_value
-  eval ac_new_val=\$ac_env_${ac_var}_value
-  case $ac_old_set,$ac_new_set in
-    set,)
-      { $as_echo "$as_me:${as_lineno-$LINENO}: error: \`$ac_var' was set to \`$ac_old_val' in the previous run" >&5
-$as_echo "$as_me: error: \`$ac_var' was set to \`$ac_old_val' in the previous run" >&2;}
-      ac_cache_corrupted=: ;;
-    ,set)
-      { $as_echo "$as_me:${as_lineno-$LINENO}: error: \`$ac_var' was not set in the previous run" >&5
-$as_echo "$as_me: error: \`$ac_var' was not set in the previous run" >&2;}
-      ac_cache_corrupted=: ;;
-    ,);;
-    *)
-      if test "x$ac_old_val" != "x$ac_new_val"; then
-	# differences in whitespace do not lead to failure.
-	ac_old_val_w=`echo x $ac_old_val`
-	ac_new_val_w=`echo x $ac_new_val`
-	if test "$ac_old_val_w" != "$ac_new_val_w"; then
-	  { $as_echo "$as_me:${as_lineno-$LINENO}: error: \`$ac_var' has changed since the previous run:" >&5
-$as_echo "$as_me: error: \`$ac_var' has changed since the previous run:" >&2;}
-	  ac_cache_corrupted=:
-	else
-	  { $as_echo "$as_me:${as_lineno-$LINENO}: warning: ignoring whitespace changes in \`$ac_var' since the previous run:" >&5
-$as_echo "$as_me: warning: ignoring whitespace changes in \`$ac_var' since the previous run:" >&2;}
-	  eval $ac_var=\$ac_old_val
-	fi
-	{ $as_echo "$as_me:${as_lineno-$LINENO}:   former value:  \`$ac_old_val'" >&5
-$as_echo "$as_me:   former value:  \`$ac_old_val'" >&2;}
-	{ $as_echo "$as_me:${as_lineno-$LINENO}:   current value: \`$ac_new_val'" >&5
-$as_echo "$as_me:   current value: \`$ac_new_val'" >&2;}
-      fi;;
-  esac
-  # Pass precious variables to config.status.
-  if test "$ac_new_set" = set; then
-    case $ac_new_val in
-    *\'*) ac_arg=$ac_var=`$as_echo "$ac_new_val" | sed "s/'/'\\\\\\\\''/g"` ;;
-    *) ac_arg=$ac_var=$ac_new_val ;;
-    esac
-    case " $ac_configure_args " in
-      *" '$ac_arg' "*) ;; # Avoid dups.  Use of quotes ensures accuracy.
-      *) as_fn_append ac_configure_args " '$ac_arg'" ;;
-    esac
-  fi
-done
-if $ac_cache_corrupted; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
-$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
-  { $as_echo "$as_me:${as_lineno-$LINENO}: error: changes in the environment can compromise the build" >&5
-$as_echo "$as_me: error: changes in the environment can compromise the build" >&2;}
-  as_fn_error $? "run \`make distclean' and/or \`rm $cache_file' and start over" "$LINENO" 5
-fi
-## -------------------- ##
-## Main body of script. ##
-## -------------------- ##
+# Test code for whether the C++ compiler supports C++98 (global declarations)
+ac_cxx_conftest_cxx98_globals='
+// Does the compiler advertise C++98 conformance?
+#if !defined __cplusplus || __cplusplus < 199711L
+# error "Compiler does not advertise C++98 conformance"
+#endif
 
-ac_ext=c
-ac_cpp='$CPP $CPPFLAGS'
-ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_c_compiler_gnu
+// These inclusions are to reject old compilers that
+// lack the unsuffixed header files.
+#include <cstdlib>
+#include <exception>
 
+// <cassert> and <cstring> are *not* freestanding headers in C++98.
+extern void assert (int);
+namespace std {
+  extern int strcmp (const char *, const char *);
+}
 
+// Namespaces, exceptions, and templates were all added after "C++ 2.0".
+using std::exception;
+using std::strcmp;
 
-##################################################################
-# In order to add m4 macros, put then in a m4 directory and include them here.
-# E.g.:
-# m4_include([./m4/m4_ax_openmp.m4])
+namespace {
 
-##################################################################
-# Here we define a few useful macros
+void test_exception_syntax()
+{
+  try {
+    throw "test";
+  } catch (const char *s) {
+    // Extra parentheses suppress a warning when building autoconf itself,
+    // due to lint rules shared with more typical C programs.
+    assert (!(strcmp) (s, "test"));
+  }
+}
 
-# PLUMED_CONFIG_ENABLE(variablename,optionname,doc,default)
-# notice that variablename and optionname are likely identical,
-# they just need to be different with optionname contains a "-"
-# (not allowed in shell variable names)
+template <typename T> struct test_template
+{
+  T const val;
+  explicit test_template(T t) : val(t) {}
+  template <typename U> T add(U u) { return static_cast<T>(u) + val; }
+};
 
+} // anonymous namespace
+'
 
-# PLUMED_CHECK_CXXFLAG(flag)
-# use it to check if a flag is available on this compiler
+# Test code for whether the C++ compiler supports C++98 (body of main)
+ac_cxx_conftest_cxx98_main='
+  assert (argc);
+  assert (! argv[0]);
+{
+  test_exception_syntax ();
+  test_template<double> tt (2.0);
+  assert (tt.add (4) == 6.0);
+  assert (true && !false);
+}
+'
 
+# Test code for whether the C++ compiler supports C++11 (global declarations)
+ac_cxx_conftest_cxx11_globals='
+// Does the compiler advertise C++ 2011 conformance?
+#if !defined __cplusplus || __cplusplus < 201103L
+# error "Compiler does not advertise C++11 conformance"
+#endif
 
-# PLUMED_CHECK_CFLAG(flag)
-# use it to check if a flag is available on this compiler
+namespace cxx11test
+{
+  constexpr int get_val() { return 20; }
 
+  struct testinit
+  {
+    int i;
+    double d;
+  };
 
-# PLUMED_CHECK_LDFLAGS(flag)
-# use it to check if a flag is available on this compiler
+  class delegate
+  {
+  public:
+    delegate(int n) : n(n) {}
+    delegate(): delegate(2354) {}
 
+    virtual int getval() { return this->n; };
+  protected:
+    int n;
+  };
 
-# PLUMED_SEARCH_LIBS(function,search-libs[,action-if-found][,action-if-not-found][,other-libraries])
-# same as AC_SEARCH_LIBS, but does not try any library unless $libsearch=true
-# Should be used instead of AC_SEARCH_LIBS in order to make --disable-libsearch work correctly
+  class overridden : public delegate
+  {
+  public:
+    overridden(int n): delegate(n) {}
+    virtual int getval() override final { return this->n * 2; }
+  };
 
+  class nocopy
+  {
+  public:
+    nocopy(int i): i(i) {}
+    nocopy() = default;
+    nocopy(const nocopy&) = delete;
+    nocopy & operator=(const nocopy&) = delete;
+  private:
+    int i;
+  };
+
+  // for testing lambda expressions
+  template <typename Ret, typename Fn> Ret eval(Fn f, Ret v)
+  {
+    return f(v);
+  }
 
-# PLUMED_CHECK_PACKAGE(header,function,define[,library])
-# first we check if the header is present. if so, we check if the given function can be found.
+  // for testing variadic templates and trailing return types
+  template <typename V> auto sum(V first) -> V
+  {
+    return first;
+  }
+  template <typename V, typename... Args> auto sum(V first, Args... rest) -> V
+  {
+    return first + sum(rest...);
+  }
+}
+'
+
+# Test code for whether the C++ compiler supports C++11 (body of main)
+ac_cxx_conftest_cxx11_main='
+{
+  // Test auto and decltype
+  auto a1 = 6538;
+  auto a2 = 48573953.4;
+  auto a3 = "String literal";
+
+  int total = 0;
+  for (auto i = a3; *i; ++i) { total += *i; }
+
+  decltype(a2) a4 = 34895.034;
+}
+{
+  // Test constexpr
+  short sa[cxx11test::get_val()] = { 0 };
+}
+{
+  // Test initializer lists
+  cxx11test::testinit il = { 4323, 435234.23544 };
+}
+{
+  // Test range-based for
+  int array[] = {9, 7, 13, 15, 4, 18, 12, 10, 5, 3,
+                 14, 19, 17, 8, 6, 20, 16, 2, 11, 1};
+  for (auto &x : array) { x += 23; }
+}
+{
+  // Test lambda expressions
+  using cxx11test::eval;
+  assert (eval ([](int x) { return x*2; }, 21) == 42);
+  double d = 2.0;
+  assert (eval ([&](double x) { return d += x; }, 3.0) == 5.0);
+  assert (d == 5.0);
+  assert (eval ([=](double x) mutable { return d += x; }, 4.0) == 9.0);
+  assert (d == 5.0);
+}
+{
+  // Test use of variadic templates
+  using cxx11test::sum;
+  auto a = sum(1);
+  auto b = sum(1, 2);
+  auto c = sum(1.0, 2.0, 3.0);
+}
+{
+  // Test constructor delegation
+  cxx11test::delegate d1;
+  cxx11test::delegate d2();
+  cxx11test::delegate d3(45);
+}
+{
+  // Test override and final
+  cxx11test::overridden o1(55464);
+}
+{
+  // Test nullptr
+  char *c = nullptr;
+}
+{
+  // Test template brackets
+  test_template<::test_template<int>> v(test_template<int>(12));
+}
+{
+  // Unicode literals
+  char const *utf8 = u8"UTF-8 string \u2500";
+  char16_t const *utf16 = u"UTF-8 string \u2500";
+  char32_t const *utf32 = U"UTF-32 string \u2500";
+}
+'
+
+# Test code for whether the C compiler supports C++11 (complete).
+ac_cxx_conftest_cxx11_program="${ac_cxx_conftest_cxx98_globals}
+${ac_cxx_conftest_cxx11_globals}
+
+int
+main (int argc, char **argv)
+{
+  int ok = 0;
+  ${ac_cxx_conftest_cxx98_main}
+  ${ac_cxx_conftest_cxx11_main}
+  return ok;
+}
+"
+
+# Test code for whether the C compiler supports C++98 (complete).
+ac_cxx_conftest_cxx98_program="${ac_cxx_conftest_cxx98_globals}
+int
+main (int argc, char **argv)
+{
+  int ok = 0;
+  ${ac_cxx_conftest_cxx98_main}
+  return ok;
+}
+"
+
+# Test code for whether the C compiler supports C89 (global declarations)
+ac_c_conftest_c89_globals='
+/* Does the compiler advertise C89 conformance?
+   Do not test the value of __STDC__, because some compilers set it to 0
+   while being otherwise adequately conformant. */
+#if !defined __STDC__
+# error "Compiler does not advertise C89 conformance"
+#endif
+
+#include <stddef.h>
+#include <stdarg.h>
+struct stat;
+/* Most of the following tests are stolen from RCS 5.7 src/conf.sh.  */
+struct buf { int x; };
+struct buf * (*rcsopen) (struct buf *, struct stat *, int);
+static char *e (char **p, int i)
+{
+  return p[i];
+}
+static char *f (char * (*g) (char **, int), char **p, ...)
+{
+  char *s;
+  va_list v;
+  va_start (v,p);
+  s = g (p, va_arg (v,int));
+  va_end (v);
+  return s;
+}
+
+/* C89 style stringification. */
+#define noexpand_stringify(a) #a
+const char *stringified = noexpand_stringify(arbitrary+token=sequence);
+
+/* C89 style token pasting.  Exercises some of the corner cases that
+   e.g. old MSVC gets wrong, but not very hard. */
+#define noexpand_concat(a,b) a##b
+#define expand_concat(a,b) noexpand_concat(a,b)
+extern int vA;
+extern int vbee;
+#define aye A
+#define bee B
+int *pvA = &expand_concat(v,aye);
+int *pvbee = &noexpand_concat(v,bee);
+
+/* OSF 4.0 Compaq cc is some sort of almost-ANSI by default.  It has
+   function prototypes and stuff, but not \xHH hex character constants.
+   These do not provoke an error unfortunately, instead are silently treated
+   as an "x".  The following induces an error, until -std is added to get
+   proper ANSI mode.  Curiously \x00 != x always comes out true, for an
+   array size at least.  It is necessary to write \x00 == 0 to get something
+   that is true only with -std.  */
+int osf4_cc_array ['\''\x00'\'' == 0 ? 1 : -1];
+
+/* IBM C 6 for AIX is almost-ANSI by default, but it replaces macro parameters
+   inside strings and character constants.  */
+#define FOO(x) '\''x'\''
+int xlc6_cc_array[FOO(a) == '\''x'\'' ? 1 : -1];
+
+int test (int i, double x);
+struct s1 {int (*f) (int a);};
+struct s2 {int (*f) (double a);};
+int pairnames (int, char **, int *(*)(struct buf *, struct stat *, int),
+               int, int);'
+
+# Test code for whether the C compiler supports C89 (body of main).
+ac_c_conftest_c89_main='
+ok |= (argc == 0 || f (e, argv, 0) != argv[0] || f (e, argv, 1) != argv[1]);
+'
+
+# Test code for whether the C compiler supports C99 (global declarations)
+ac_c_conftest_c99_globals='
+/* Does the compiler advertise C99 conformance? */
+#if !defined __STDC_VERSION__ || __STDC_VERSION__ < 199901L
+# error "Compiler does not advertise C99 conformance"
+#endif
+
+// See if C++-style comments work.
+
+#include <stdbool.h>
+extern int puts (const char *);
+extern int printf (const char *, ...);
+extern int dprintf (int, const char *, ...);
+extern void *malloc (size_t);
+extern void free (void *);
+
+// Check varargs macros.  These examples are taken from C99 6.10.3.5.
+// dprintf is used instead of fprintf to avoid needing to declare
+// FILE and stderr.
+#define debug(...) dprintf (2, __VA_ARGS__)
+#define showlist(...) puts (#__VA_ARGS__)
+#define report(test,...) ((test) ? puts (#test) : printf (__VA_ARGS__))
+static void
+test_varargs_macros (void)
+{
+  int x = 1234;
+  int y = 5678;
+  debug ("Flag");
+  debug ("X = %d\n", x);
+  showlist (The first, second, and third items.);
+  report (x>y, "x is %d but y is %d", x, y);
+}
+
+// Check long long types.
+#define BIG64 18446744073709551615ull
+#define BIG32 4294967295ul
+#define BIG_OK (BIG64 / BIG32 == 4294967297ull && BIG64 % BIG32 == 0)
+#if !BIG_OK
+  #error "your preprocessor is broken"
+#endif
+#if BIG_OK
+#else
+  #error "your preprocessor is broken"
+#endif
+static long long int bignum = -9223372036854775807LL;
+static unsigned long long int ubignum = BIG64;
+
+struct incomplete_array
+{
+  int datasize;
+  double data[];
+};
+
+struct named_init {
+  int number;
+  const wchar_t *name;
+  double average;
+};
+
+typedef const char *ccp;
+
+static inline int
+test_restrict (ccp restrict text)
+{
+  // Iterate through items via the restricted pointer.
+  // Also check for declarations in for loops.
+  for (unsigned int i = 0; *(text+i) != '\''\0'\''; ++i)
+    continue;
+  return 0;
+}
+
+// Check varargs and va_copy.
+static bool
+test_varargs (const char *format, ...)
+{
+  va_list args;
+  va_start (args, format);
+  va_list args_copy;
+  va_copy (args_copy, args);
+
+  const char *str = "";
+  int number = 0;
+  float fnumber = 0;
+
+  while (*format)
+    {
+      switch (*format++)
+	{
+	case '\''s'\'': // string
+	  str = va_arg (args_copy, const char *);
+	  break;
+	case '\''d'\'': // int
+	  number = va_arg (args_copy, int);
+	  break;
+	case '\''f'\'': // float
+	  fnumber = va_arg (args_copy, double);
+	  break;
+	default:
+	  break;
+	}
+    }
+  va_end (args_copy);
+  va_end (args);
+
+  return *str && number && fnumber;
+}
+'
+
+# Test code for whether the C compiler supports C99 (body of main).
+ac_c_conftest_c99_main='
+  // Check bool.
+  _Bool success = false;
+  success |= (argc != 0);
+
+  // Check restrict.
+  if (test_restrict ("String literal") == 0)
+    success = true;
+  char *restrict newvar = "Another string";
+
+  // Check varargs.
+  success &= test_varargs ("s, d'\'' f .", "string", 65, 34.234);
+  test_varargs_macros ();
+
+  // Check flexible array members.
+  struct incomplete_array *ia =
+    malloc (sizeof (struct incomplete_array) + (sizeof (double) * 10));
+  ia->datasize = 10;
+  for (int i = 0; i < ia->datasize; ++i)
+    ia->data[i] = i * 1.234;
+  // Work around memory leak warnings.
+  free (ia);
+
+  // Check named initializers.
+  struct named_init ni = {
+    .number = 34,
+    .name = L"Test wide string",
+    .average = 543.34343,
+  };
+
+  ni.number = 58;
+
+  int dynamic_array[ni.number];
+  dynamic_array[0] = argv[0][0];
+  dynamic_array[ni.number - 1] = 543;
+
+  // work around unused variable warnings
+  ok |= (!success || bignum == 0LL || ubignum == 0uLL || newvar[0] == '\''x'\''
+	 || dynamic_array[ni.number - 1] != 543);
+'
+
+# Test code for whether the C compiler supports C11 (global declarations)
+ac_c_conftest_c11_globals='
+/* Does the compiler advertise C11 conformance? */
+#if !defined __STDC_VERSION__ || __STDC_VERSION__ < 201112L
+# error "Compiler does not advertise C11 conformance"
+#endif
+
+// Check _Alignas.
+char _Alignas (double) aligned_as_double;
+char _Alignas (0) no_special_alignment;
+extern char aligned_as_int;
+char _Alignas (0) _Alignas (int) aligned_as_int;
+
+// Check _Alignof.
+enum
+{
+  int_alignment = _Alignof (int),
+  int_array_alignment = _Alignof (int[100]),
+  char_alignment = _Alignof (char)
+};
+_Static_assert (0 < -_Alignof (int), "_Alignof is signed");
+
+// Check _Noreturn.
+int _Noreturn does_not_return (void) { for (;;) continue; }
+
+// Check _Static_assert.
+struct test_static_assert
+{
+  int x;
+  _Static_assert (sizeof (int) <= sizeof (long int),
+                  "_Static_assert does not work in struct");
+  long int y;
+};
+
+// Check UTF-8 literals.
+#define u8 syntax error!
+char const utf8_literal[] = u8"happens to be ASCII" "another string";
+
+// Check duplicate typedefs.
+typedef long *long_ptr;
+typedef long int *long_ptr;
+typedef long_ptr long_ptr;
+
+// Anonymous structures and unions -- taken from C11 6.7.2.1 Example 1.
+struct anonymous
+{
+  union {
+    struct { int i; int j; };
+    struct { int k; long int l; } w;
+  };
+  int m;
+} v1;
+'
+
+# Test code for whether the C compiler supports C11 (body of main).
+ac_c_conftest_c11_main='
+  _Static_assert ((offsetof (struct anonymous, i)
+		   == offsetof (struct anonymous, w.k)),
+		  "Anonymous union alignment botch");
+  v1.i = 2;
+  v1.w.k = 5;
+  ok |= v1.i != 5;
+'
+
+# Test code for whether the C compiler supports C11 (complete).
+ac_c_conftest_c11_program="${ac_c_conftest_c89_globals}
+${ac_c_conftest_c99_globals}
+${ac_c_conftest_c11_globals}
+
+int
+main (int argc, char **argv)
+{
+  int ok = 0;
+  ${ac_c_conftest_c89_main}
+  ${ac_c_conftest_c99_main}
+  ${ac_c_conftest_c11_main}
+  return ok;
+}
+"
+
+# Test code for whether the C compiler supports C99 (complete).
+ac_c_conftest_c99_program="${ac_c_conftest_c89_globals}
+${ac_c_conftest_c99_globals}
+
+int
+main (int argc, char **argv)
+{
+  int ok = 0;
+  ${ac_c_conftest_c89_main}
+  ${ac_c_conftest_c99_main}
+  return ok;
+}
+"
+
+# Test code for whether the C compiler supports C89 (complete).
+ac_c_conftest_c89_program="${ac_c_conftest_c89_globals}
+
+int
+main (int argc, char **argv)
+{
+  int ok = 0;
+  ${ac_c_conftest_c89_main}
+  return ok;
+}
+"
+
+as_fn_append ac_header_cxx_list " stdio.h stdio_h HAVE_STDIO_H"
+as_fn_append ac_header_cxx_list " stdlib.h stdlib_h HAVE_STDLIB_H"
+as_fn_append ac_header_cxx_list " string.h string_h HAVE_STRING_H"
+as_fn_append ac_header_cxx_list " inttypes.h inttypes_h HAVE_INTTYPES_H"
+as_fn_append ac_header_cxx_list " stdint.h stdint_h HAVE_STDINT_H"
+as_fn_append ac_header_cxx_list " strings.h strings_h HAVE_STRINGS_H"
+as_fn_append ac_header_cxx_list " sys/stat.h sys_stat_h HAVE_SYS_STAT_H"
+as_fn_append ac_header_cxx_list " sys/types.h sys_types_h HAVE_SYS_TYPES_H"
+as_fn_append ac_header_cxx_list " unistd.h unistd_h HAVE_UNISTD_H"
+# Check that the precious variables saved in the cache have kept the same
+# value.
+ac_cache_corrupted=false
+for ac_var in $ac_precious_vars; do
+  eval ac_old_set=\$ac_cv_env_${ac_var}_set
+  eval ac_new_set=\$ac_env_${ac_var}_set
+  eval ac_old_val=\$ac_cv_env_${ac_var}_value
+  eval ac_new_val=\$ac_env_${ac_var}_value
+  case $ac_old_set,$ac_new_set in
+    set,)
+      { printf "%s\n" "$as_me:${as_lineno-$LINENO}: error: '$ac_var' was set to '$ac_old_val' in the previous run" >&5
+printf "%s\n" "$as_me: error: '$ac_var' was set to '$ac_old_val' in the previous run" >&2;}
+      ac_cache_corrupted=: ;;
+    ,set)
+      { printf "%s\n" "$as_me:${as_lineno-$LINENO}: error: '$ac_var' was not set in the previous run" >&5
+printf "%s\n" "$as_me: error: '$ac_var' was not set in the previous run" >&2;}
+      ac_cache_corrupted=: ;;
+    ,);;
+    *)
+      if test "x$ac_old_val" != "x$ac_new_val"; then
+	# differences in whitespace do not lead to failure.
+	ac_old_val_w=`echo x $ac_old_val`
+	ac_new_val_w=`echo x $ac_new_val`
+	if test "$ac_old_val_w" != "$ac_new_val_w"; then
+	  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: error: '$ac_var' has changed since the previous run:" >&5
+printf "%s\n" "$as_me: error: '$ac_var' has changed since the previous run:" >&2;}
+	  ac_cache_corrupted=:
+	else
+	  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: warning: ignoring whitespace changes in '$ac_var' since the previous run:" >&5
+printf "%s\n" "$as_me: warning: ignoring whitespace changes in '$ac_var' since the previous run:" >&2;}
+	  eval $ac_var=\$ac_old_val
+	fi
+	{ printf "%s\n" "$as_me:${as_lineno-$LINENO}:   former value:  '$ac_old_val'" >&5
+printf "%s\n" "$as_me:   former value:  '$ac_old_val'" >&2;}
+	{ printf "%s\n" "$as_me:${as_lineno-$LINENO}:   current value: '$ac_new_val'" >&5
+printf "%s\n" "$as_me:   current value: '$ac_new_val'" >&2;}
+      fi;;
+  esac
+  # Pass precious variables to config.status.
+  if test "$ac_new_set" = set; then
+    case $ac_new_val in
+    *\'*) ac_arg=$ac_var=`printf "%s\n" "$ac_new_val" | sed "s/'/'\\\\\\\\''/g"` ;;
+    *) ac_arg=$ac_var=$ac_new_val ;;
+    esac
+    case " $ac_configure_args " in
+      *" '$ac_arg' "*) ;; # Avoid dups.  Use of quotes ensures accuracy.
+      *) as_fn_append ac_configure_args " '$ac_arg'" ;;
+    esac
+  fi
+done
+if $ac_cache_corrupted; then
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: error: in '$ac_pwd':" >&5
+printf "%s\n" "$as_me: error: in '$ac_pwd':" >&2;}
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: error: changes in the environment can compromise the build" >&5
+printf "%s\n" "$as_me: error: changes in the environment can compromise the build" >&2;}
+  as_fn_error $? "run '${MAKE-make} distclean' and/or 'rm $cache_file'
+	    and start over" "$LINENO" 5
+fi
+## -------------------- ##
+## Main body of script. ##
+## -------------------- ##
+
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+
+
+##################################################################
+# In order to add m4 macros, put then in a m4 directory and include them here.
+# E.g.:
+# m4_include([./m4/m4_ax_openmp.m4])
+
+##################################################################
+# Here we define a few useful macros
+
+# PLUMED_CONFIG_ENABLE(variablename,optionname,doc,default)
+# notice that variablename and optionname are likely identical,
+# they just need to be different with optionname contains a "-"
+# (not allowed in shell variable names)
+
+
+# PLUMED_CHECK_CXXFLAG(flag)
+# use it to check if a flag is available on this compiler
+
+
+# PLUMED_CHECK_CFLAG(flag)
+# use it to check if a flag is available on this compiler
+
+
+# PLUMED_CHECK_LDFLAGS(flag)
+# use it to check if a flag is available on this compiler
+
+
+# PLUMED_SEARCH_LIBS(function,search-libs[,action-if-found][,action-if-not-found][,other-libraries])
+# same as AC_SEARCH_LIBS, but does not try any library unless $libsearch=true
+# Should be used instead of AC_SEARCH_LIBS in order to make --disable-libsearch work correctly
+
+
+# PLUMED_CHECK_PACKAGE(header,function,define[,library])
+# first we check if the header is present. if so, we check if the given function can be found.
 # if it cannot be found and the fourth argument (library) has been supplied, we look for it
 # in the library. finally, we set the define flag
 
@@ -2365,12 +2846,13 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
 ##################################################################
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: Optional modules are disabled by default" >&5
-$as_echo "$as_me: Optional modules are disabled by default" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: Optional modules are disabled by default" >&5
+printf "%s\n" "$as_me: Optional modules are disabled by default" >&6;}
 rm -f src/*.on src/*.off
 
 # Check whether --enable-modules was given.
-if test "${enable_modules+set}" = set; then :
+if test ${enable_modules+y}
+then :
   enableval=$enable_modules;
    rm -f src/*.on src/*.off
    if test "${enableval}" = yes ; then
@@ -2383,18 +2865,18 @@ if test "${enable_modules+set}" = set; then :
    do
      case "$modules_mod" in
      (none)
-       { $as_echo "$as_me:${as_lineno-$LINENO}: Disabling all optional modules" >&5
-$as_echo "$as_me: Disabling all optional modules" >&6;}
+       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Disabling all optional modules" >&5
+printf "%s\n" "$as_me: Disabling all optional modules" >&6;}
        rm -f src/*.off src/*.on
        touch $(grep default-on src/*/module.type | sed "s|/module.type:.*|.off|") ;;
      (all)
-       { $as_echo "$as_me:${as_lineno-$LINENO}: Enabling all optional modules" >&5
-$as_echo "$as_me: Enabling all optional modules" >&6;}
+       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Enabling all optional modules" >&5
+printf "%s\n" "$as_me: Enabling all optional modules" >&6;}
        rm -f src/*.off src/*.off
        touch $(grep default-off src/*/module.type | sed "s|/module.type:.*|.on|") ;;
      (reset)
-        { $as_echo "$as_me:${as_lineno-$LINENO}: Resetting modules to default" >&5
-$as_echo "$as_me: Resetting modules to default" >&6;}
+        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Resetting modules to default" >&5
+printf "%s\n" "$as_me: Resetting modules to default" >&6;}
         rm -f src/*.on src/*.off ;;
      (-*)
        modules_mod=`echo "${modules_mod}" | sed "s|-||"`
@@ -2404,8 +2886,8 @@ $as_echo "$as_me: Resetting modules to default" >&6;}
        if grep -q always src/$modules_mod/module.type ; then
          as_fn_error $? "trying to remove module $modules_mod which is always enabled" "$LINENO" 5
        fi
-       { $as_echo "$as_me:${as_lineno-$LINENO}: Disabling module ${modules_mod}" >&5
-$as_echo "$as_me: Disabling module ${modules_mod}" >&6;}
+       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Disabling module ${modules_mod}" >&5
+printf "%s\n" "$as_me: Disabling module ${modules_mod}" >&6;}
        rm -f src/$modules_mod.on
        touch src/$modules_mod.off ;;
      (+*)
@@ -2413,16 +2895,16 @@ $as_echo "$as_me: Disabling module ${modules_mod}" >&6;}
        if test ! -f src/$modules_mod/module.type ; then
          as_fn_error $? "trying to add module $modules_mod which does not exist" "$LINENO" 5
        fi
-       { $as_echo "$as_me:${as_lineno-$LINENO}: Enabling module ${modules_mod}" >&5
-$as_echo "$as_me: Enabling module ${modules_mod}" >&6;}
+       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Enabling module ${modules_mod}" >&5
+printf "%s\n" "$as_me: Enabling module ${modules_mod}" >&6;}
        rm -f src/$modules_mod.off
        touch src/$modules_mod.on ;;
      (*)
        if test ! -f src/$modules_mod/module.type ; then
          as_fn_error $? "trying to add module $modules_mod which does not exist" "$LINENO" 5
        fi
-       { $as_echo "$as_me:${as_lineno-$LINENO}: Enabling module ${modules_mod}" >&5
-$as_echo "$as_me: Enabling module ${modules_mod}" >&6;}
+       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Enabling module ${modules_mod}" >&5
+printf "%s\n" "$as_me: Enabling module ${modules_mod}" >&6;}
        rm -f src/$modules_mod.off
        touch src/$modules_mod.on ;;
      esac
@@ -2441,18 +2923,20 @@ fi
 
 libsearch=
 # Check whether --enable-libsearch was given.
-if test "${enable_libsearch+set}" = set; then :
+if test ${enable_libsearch+y}
+then :
   enableval=$enable_libsearch; case "${enableval}" in
              (yes) libsearch=true ;;
              (no)  libsearch=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-libsearch" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) libsearch=true ;;
              (no)  libsearch=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
@@ -2463,18 +2947,20 @@ fi
 
 static_patch=
 # Check whether --enable-static-patch was given.
-if test "${enable_static_patch+set}" = set; then :
+if test ${enable_static_patch+y}
+then :
   enableval=$enable_static_patch; case "${enableval}" in
              (yes) static_patch=true ;;
              (no)  static_patch=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-static-patch" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) static_patch=true ;;
              (no)  static_patch=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
@@ -2482,77 +2968,86 @@ fi
 
 doc=
 # Check whether --enable-doc was given.
-if test "${enable_doc+set}" = set; then :
+if test ${enable_doc+y}
+then :
   enableval=$enable_doc; case "${enableval}" in
              (yes) doc=true ;;
              (no)  doc=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-doc" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) doc=true ;;
              (no)  doc=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 pdfdoc=
 # Check whether --enable-pdfdoc was given.
-if test "${enable_pdfdoc+set}" = set; then :
+if test ${enable_pdfdoc+y}
+then :
   enableval=$enable_pdfdoc; case "${enableval}" in
              (yes) pdfdoc=true ;;
              (no)  pdfdoc=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-pdfdoc" "$LINENO" 5 ;;
   esac
-else
-  case "no" in
+else case e in #(
+  e) case "no" in
              (yes) pdfdoc=true ;;
              (no)  pdfdoc=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 debug=
 # Check whether --enable-debug was given.
-if test "${enable_debug+set}" = set; then :
+if test ${enable_debug+y}
+then :
   enableval=$enable_debug; case "${enableval}" in
              (yes) debug=true ;;
              (no)  debug=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-debug" "$LINENO" 5 ;;
   esac
-else
-  case "no" in
+else case e in #(
+  e) case "no" in
              (yes) debug=true ;;
              (no)  debug=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 gcov=
 # Check whether --enable-gcov was given.
-if test "${enable_gcov+set}" = set; then :
+if test ${enable_gcov+y}
+then :
   enableval=$enable_gcov; case "${enableval}" in
              (yes) gcov=true ;;
              (no)  gcov=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-gcov" "$LINENO" 5 ;;
   esac
-else
-  case "no" in
+else case e in #(
+  e) case "no" in
              (yes) gcov=true ;;
              (no)  gcov=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 # Check whether --enable-cxx was given.
-if test "${enable_cxx+set}" = set; then :
+if test ${enable_cxx+y}
+then :
   enableval=$enable_cxx;
     case "${enableval}" in
     (11) cxx_level=17 ;;
@@ -2563,683 +3058,778 @@ if test "${enable_cxx+set}" = set; then :
     (none) cxx_level="" ;;
     (*) as_fn_error $? "cxx level not supported" "$LINENO" 5
     esac
-    { $as_echo "$as_me:${as_lineno-$LINENO}: Selected C++ level: $cxx_level" >&5
-$as_echo "$as_me: Selected C++ level: $cxx_level" >&6;}
-
-else
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Selected C++ level: $cxx_level" >&5
+printf "%s\n" "$as_me: Selected C++ level: $cxx_level" >&6;}
 
+else case e in #(
+  e)
     cxx_level="17"
 
-
+ ;;
+esac
 fi
 
 
 basic_warnings=
 # Check whether --enable-basic-warnings was given.
-if test "${enable_basic_warnings+set}" = set; then :
+if test ${enable_basic_warnings+y}
+then :
   enableval=$enable_basic_warnings; case "${enableval}" in
              (yes) basic_warnings=true ;;
              (no)  basic_warnings=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-basic-warnings" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) basic_warnings=true ;;
              (no)  basic_warnings=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 fussy=
 # Check whether --enable-fussy was given.
-if test "${enable_fussy+set}" = set; then :
+if test ${enable_fussy+y}
+then :
   enableval=$enable_fussy; case "${enableval}" in
              (yes) fussy=true ;;
              (no)  fussy=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-fussy" "$LINENO" 5 ;;
   esac
-else
-  case "no" in
+else case e in #(
+  e) case "no" in
              (yes) fussy=true ;;
              (no)  fussy=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 debug_glibcxx=
 # Check whether --enable-debug-glibcxx was given.
-if test "${enable_debug_glibcxx+set}" = set; then :
+if test ${enable_debug_glibcxx+y}
+then :
   enableval=$enable_debug_glibcxx; case "${enableval}" in
              (yes) debug_glibcxx=true ;;
              (no)  debug_glibcxx=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-debug-glibcxx" "$LINENO" 5 ;;
   esac
-else
-  case "no" in
+else case e in #(
+  e) case "no" in
              (yes) debug_glibcxx=true ;;
              (no)  debug_glibcxx=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 shared=
 # Check whether --enable-shared was given.
-if test "${enable_shared+set}" = set; then :
+if test ${enable_shared+y}
+then :
   enableval=$enable_shared; case "${enableval}" in
              (yes) shared=true ;;
              (no)  shared=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-shared" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) shared=true ;;
              (no)  shared=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 dependency_tracking=
 # Check whether --enable-dependency-tracking was given.
-if test "${enable_dependency_tracking+set}" = set; then :
+if test ${enable_dependency_tracking+y}
+then :
   enableval=$enable_dependency_tracking; case "${enableval}" in
              (yes) dependency_tracking=true ;;
              (no)  dependency_tracking=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-dependency-tracking" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) dependency_tracking=true ;;
              (no)  dependency_tracking=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 no_gnu_unique=
 # Check whether --enable-no-gnu-unique was given.
-if test "${enable_no_gnu_unique+set}" = set; then :
+if test ${enable_no_gnu_unique+y}
+then :
   enableval=$enable_no_gnu_unique; case "${enableval}" in
              (yes) no_gnu_unique=true ;;
              (no)  no_gnu_unique=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-no-gnu-unique" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) no_gnu_unique=true ;;
              (no)  no_gnu_unique=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 rpath=
 # Check whether --enable-rpath was given.
-if test "${enable_rpath+set}" = set; then :
+if test ${enable_rpath+y}
+then :
   enableval=$enable_rpath; case "${enableval}" in
              (yes) rpath=true ;;
              (no)  rpath=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-rpath" "$LINENO" 5 ;;
   esac
-else
-  case "no" in
+else case e in #(
+  e) case "no" in
              (yes) rpath=true ;;
              (no)  rpath=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 absolute_soname=
 # Check whether --enable-absolute-soname was given.
-if test "${enable_absolute_soname+set}" = set; then :
+if test ${enable_absolute_soname+y}
+then :
   enableval=$enable_absolute_soname; case "${enableval}" in
              (yes) absolute_soname=true ;;
              (no)  absolute_soname=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-absolute-soname" "$LINENO" 5 ;;
   esac
-else
-  case "no" in
+else case e in #(
+  e) case "no" in
              (yes) absolute_soname=true ;;
              (no)  absolute_soname=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 absolute_install_name=
 # Check whether --enable-absolute-install-name was given.
-if test "${enable_absolute_install_name+set}" = set; then :
+if test ${enable_absolute_install_name+y}
+then :
   enableval=$enable_absolute_install_name; case "${enableval}" in
              (yes) absolute_install_name=true ;;
              (no)  absolute_install_name=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-absolute-install-name" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) absolute_install_name=true ;;
              (no)  absolute_install_name=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 loader_path=
 # Check whether --enable-loader-path was given.
-if test "${enable_loader_path+set}" = set; then :
+if test ${enable_loader_path+y}
+then :
   enableval=$enable_loader_path; case "${enableval}" in
              (yes) loader_path=true ;;
              (no)  loader_path=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-loader-path" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) loader_path=true ;;
              (no)  loader_path=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 bsymbolic=
 # Check whether --enable-bsymbolic was given.
-if test "${enable_bsymbolic+set}" = set; then :
+if test ${enable_bsymbolic+y}
+then :
   enableval=$enable_bsymbolic; case "${enableval}" in
              (yes) bsymbolic=true ;;
              (no)  bsymbolic=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-bsymbolic" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) bsymbolic=true ;;
              (no)  bsymbolic=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 ld_r=
 # Check whether --enable-ld-r was given.
-if test "${enable_ld_r+set}" = set; then :
+if test ${enable_ld_r+y}
+then :
   enableval=$enable_ld_r; case "${enableval}" in
              (yes) ld_r=true ;;
              (no)  ld_r=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-ld-r" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) ld_r=true ;;
              (no)  ld_r=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 ar_cr=
 # Check whether --enable-ar-cr was given.
-if test "${enable_ar_cr+set}" = set; then :
+if test ${enable_ar_cr+y}
+then :
   enableval=$enable_ar_cr; case "${enableval}" in
              (yes) ar_cr=true ;;
              (no)  ar_cr=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-ar-cr" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) ar_cr=true ;;
              (no)  ar_cr=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 static_archive=
 # Check whether --enable-static-archive was given.
-if test "${enable_static_archive+set}" = set; then :
+if test ${enable_static_archive+y}
+then :
   enableval=$enable_static_archive; case "${enableval}" in
              (yes) static_archive=true ;;
              (no)  static_archive=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-static-archive" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) static_archive=true ;;
              (no)  static_archive=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 asmjit=
 # Check whether --enable-asmjit was given.
-if test "${enable_asmjit+set}" = set; then :
+if test ${enable_asmjit+y}
+then :
   enableval=$enable_asmjit; case "${enableval}" in
              (yes) asmjit=true ;;
              (no)  asmjit=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-asmjit" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) asmjit=true ;;
              (no)  asmjit=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 mpi=
 # Check whether --enable-mpi was given.
-if test "${enable_mpi+set}" = set; then :
+if test ${enable_mpi+y}
+then :
   enableval=$enable_mpi; case "${enableval}" in
              (yes) mpi=true ;;
              (no)  mpi=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-mpi" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) mpi=true ;;
              (no)  mpi=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 external_lapack=
 # Check whether --enable-external-lapack was given.
-if test "${enable_external_lapack+set}" = set; then :
+if test ${enable_external_lapack+y}
+then :
   enableval=$enable_external_lapack; case "${enableval}" in
              (yes) external_lapack=true ;;
              (no)  external_lapack=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-external-lapack" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) external_lapack=true ;;
              (no)  external_lapack=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 external_blas=
 # Check whether --enable-external-blas was given.
-if test "${enable_external_blas+set}" = set; then :
+if test ${enable_external_blas+y}
+then :
   enableval=$enable_external_blas; case "${enableval}" in
              (yes) external_blas=true ;;
              (no)  external_blas=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-external-blas" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) external_blas=true ;;
              (no)  external_blas=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 molfile_plugins=
 # Check whether --enable-molfile-plugins was given.
-if test "${enable_molfile_plugins+set}" = set; then :
+if test ${enable_molfile_plugins+y}
+then :
   enableval=$enable_molfile_plugins; case "${enableval}" in
              (yes) molfile_plugins=true ;;
              (no)  molfile_plugins=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-molfile-plugins" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) molfile_plugins=true ;;
              (no)  molfile_plugins=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 external_molfile_plugins=
 # Check whether --enable-external-molfile-plugins was given.
-if test "${enable_external_molfile_plugins+set}" = set; then :
+if test ${enable_external_molfile_plugins+y}
+then :
   enableval=$enable_external_molfile_plugins; case "${enableval}" in
              (yes) external_molfile_plugins=true ;;
              (no)  external_molfile_plugins=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-external-molfile-plugins" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) external_molfile_plugins=true ;;
              (no)  external_molfile_plugins=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 zlib=
 # Check whether --enable-zlib was given.
-if test "${enable_zlib+set}" = set; then :
+if test ${enable_zlib+y}
+then :
   enableval=$enable_zlib; case "${enableval}" in
              (yes) zlib=true ;;
              (no)  zlib=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-zlib" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) zlib=true ;;
              (no)  zlib=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 dlopen=
 # Check whether --enable-dlopen was given.
-if test "${enable_dlopen+set}" = set; then :
+if test ${enable_dlopen+y}
+then :
   enableval=$enable_dlopen; case "${enableval}" in
              (yes) dlopen=true ;;
              (no)  dlopen=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-dlopen" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) dlopen=true ;;
              (no)  dlopen=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 dladdr=
 # Check whether --enable-dladdr was given.
-if test "${enable_dladdr+set}" = set; then :
+if test ${enable_dladdr+y}
+then :
   enableval=$enable_dladdr; case "${enableval}" in
              (yes) dladdr=true ;;
              (no)  dladdr=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-dladdr" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) dladdr=true ;;
              (no)  dladdr=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 rtld_default=
 # Check whether --enable-rtld_default was given.
-if test "${enable_rtld_default+set}" = set; then :
+if test ${enable_rtld_default+y}
+then :
   enableval=$enable_rtld_default; case "${enableval}" in
              (yes) rtld_default=true ;;
              (no)  rtld_default=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-rtld_default" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) rtld_default=true ;;
              (no)  rtld_default=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 subprocess=
 # Check whether --enable-subprocess was given.
-if test "${enable_subprocess+set}" = set; then :
+if test ${enable_subprocess+y}
+then :
   enableval=$enable_subprocess; case "${enableval}" in
              (yes) subprocess=true ;;
              (no)  subprocess=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-subprocess" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) subprocess=true ;;
              (no)  subprocess=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 popen=
 # Check whether --enable-popen was given.
-if test "${enable_popen+set}" = set; then :
+if test ${enable_popen+y}
+then :
   enableval=$enable_popen; case "${enableval}" in
              (yes) popen=true ;;
              (no)  popen=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-popen" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) popen=true ;;
              (no)  popen=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 execinfo=
 # Check whether --enable-execinfo was given.
-if test "${enable_execinfo+set}" = set; then :
+if test ${enable_execinfo+y}
+then :
   enableval=$enable_execinfo; case "${enableval}" in
              (yes) execinfo=true ;;
              (no)  execinfo=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-execinfo" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) execinfo=true ;;
              (no)  execinfo=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 gsl=
 # Check whether --enable-gsl was given.
-if test "${enable_gsl+set}" = set; then :
+if test ${enable_gsl+y}
+then :
   enableval=$enable_gsl; case "${enableval}" in
              (yes) gsl=true ;;
              (no)  gsl=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-gsl" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) gsl=true ;;
              (no)  gsl=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 boost_graph=
 # Check whether --enable-boost_graph was given.
-if test "${enable_boost_graph+set}" = set; then :
+if test ${enable_boost_graph+y}
+then :
   enableval=$enable_boost_graph; case "${enableval}" in
              (yes) boost_graph=true ;;
              (no)  boost_graph=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-boost_graph" "$LINENO" 5 ;;
   esac
-else
-  case "no" in
+else case e in #(
+  e) case "no" in
              (yes) boost_graph=true ;;
              (no)  boost_graph=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 boost_serialization=
 # Check whether --enable-boost_serialization was given.
-if test "${enable_boost_serialization+set}" = set; then :
+if test ${enable_boost_serialization+y}
+then :
   enableval=$enable_boost_serialization; case "${enableval}" in
              (yes) boost_serialization=true ;;
              (no)  boost_serialization=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-boost_serialization" "$LINENO" 5 ;;
   esac
-else
-  case "no" in
+else case e in #(
+  e) case "no" in
              (yes) boost_serialization=true ;;
              (no)  boost_serialization=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 fftw=
 # Check whether --enable-fftw was given.
-if test "${enable_fftw+set}" = set; then :
+if test ${enable_fftw+y}
+then :
   enableval=$enable_fftw; case "${enableval}" in
              (yes) fftw=true ;;
              (no)  fftw=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-fftw" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) fftw=true ;;
              (no)  fftw=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 python=
 # Check whether --enable-python was given.
-if test "${enable_python+set}" = set; then :
+if test ${enable_python+y}
+then :
   enableval=$enable_python; case "${enableval}" in
              (yes) python=true ;;
              (no)  python=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-python" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) python=true ;;
              (no)  python=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 pycv=
 # Check whether --enable-pycv was given.
-if test "${enable_pycv+set}" = set; then :
+if test ${enable_pycv+y}
+then :
   enableval=$enable_pycv; case "${enableval}" in
              (yes) pycv=true ;;
              (no)  pycv=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-pycv" "$LINENO" 5 ;;
   esac
-else
-  case "yes" in
+else case e in #(
+  e) case "yes" in
              (yes) pycv=true ;;
              (no)  pycv=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 af_ocl=
 # Check whether --enable-af_ocl was given.
-if test "${enable_af_ocl+set}" = set; then :
+if test ${enable_af_ocl+y}
+then :
   enableval=$enable_af_ocl; case "${enableval}" in
              (yes) af_ocl=true ;;
              (no)  af_ocl=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-af_ocl" "$LINENO" 5 ;;
   esac
-else
-  case "no" in
+else case e in #(
+  e) case "no" in
              (yes) af_ocl=true ;;
              (no)  af_ocl=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 af_cuda=
 # Check whether --enable-af_cuda was given.
-if test "${enable_af_cuda+set}" = set; then :
+if test ${enable_af_cuda+y}
+then :
   enableval=$enable_af_cuda; case "${enableval}" in
              (yes) af_cuda=true ;;
              (no)  af_cuda=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-af_cuda" "$LINENO" 5 ;;
   esac
-else
-  case "no" in
+else case e in #(
+  e) case "no" in
              (yes) af_cuda=true ;;
              (no)  af_cuda=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 af_cpu=
 # Check whether --enable-af_cpu was given.
-if test "${enable_af_cpu+set}" = set; then :
+if test ${enable_af_cpu+y}
+then :
   enableval=$enable_af_cpu; case "${enableval}" in
              (yes) af_cpu=true ;;
              (no)  af_cpu=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-af_cpu" "$LINENO" 5 ;;
   esac
-else
-  case "no" in
+else case e in #(
+  e) case "no" in
              (yes) af_cpu=true ;;
              (no)  af_cpu=false ;;
   esac
-
+ ;;
+esac
 fi
 
 
 
 libtorch=
 # Check whether --enable-libtorch was given.
-if test "${enable_libtorch+set}" = set; then :
+if test ${enable_libtorch+y}
+then :
   enableval=$enable_libtorch; case "${enableval}" in
              (yes) libtorch=true ;;
              (no)  libtorch=false ;;
              (*)   as_fn_error $? "wrong argument to --enable-libtorch" "$LINENO" 5 ;;
   esac
-else
-  case "no" in
+else case e in #(
+  e) case "no" in
              (yes) libtorch=true ;;
              (no)  libtorch=false ;;
   esac
-
+ ;;
+esac
 fi
 
  #added by luigibonati
 
+metatensor=
+# Check whether --enable-metatensor was given.
+if test ${enable_metatensor+y}
+then :
+  enableval=$enable_metatensor; case "${enableval}" in
+             (yes) metatensor=true ;;
+             (no)  metatensor=false ;;
+             (*)   as_fn_error $? "wrong argument to --enable-metatensor" "$LINENO" 5 ;;
+  esac
+else case e in #(
+  e) case "no" in
+             (yes) metatensor=true ;;
+             (no)  metatensor=false ;;
+  esac
+ ;;
+esac
+fi
+
+
+
 
 
 
@@ -3273,6 +3863,12 @@ compilers="mpic++ mpicxx mpiicpc openmpic++ openmpicxx $compilers"
 fi
 
 # do the actual search
+
+
+
+
+
+
 ac_ext=cpp
 ac_cpp='$CXXCPP $CPPFLAGS'
 ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
@@ -3287,38 +3883,44 @@ if test -z "$CXX"; then
   do
     # Extract the first word of "$ac_tool_prefix$ac_prog", so it can be a program name with args.
 set dummy $ac_tool_prefix$ac_prog; ac_word=$2
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
-$as_echo_n "checking for $ac_word... " >&6; }
-if ${ac_cv_prog_CXX+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  if test -n "$CXX"; then
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+printf %s "checking for $ac_word... " >&6; }
+if test ${ac_cv_prog_CXX+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) if test -n "$CXX"; then
   ac_cv_prog_CXX="$CXX" # Let the user override the test.
 else
 as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
 for as_dir in $PATH
 do
   IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
+  case $as_dir in #(((
+    '') as_dir=./ ;;
+    */) ;;
+    *) as_dir=$as_dir/ ;;
+  esac
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+  if as_fn_executable_p "$as_dir$ac_word$ac_exec_ext"; then
     ac_cv_prog_CXX="$ac_tool_prefix$ac_prog"
-    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    printf "%s\n" "$as_me:${as_lineno-$LINENO}: found $as_dir$ac_word$ac_exec_ext" >&5
     break 2
   fi
 done
   done
 IFS=$as_save_IFS
 
-fi
+fi ;;
+esac
 fi
 CXX=$ac_cv_prog_CXX
 if test -n "$CXX"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $CXX" >&5
-$as_echo "$CXX" >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $CXX" >&5
+printf "%s\n" "$CXX" >&6; }
 else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
 fi
 
 
@@ -3331,38 +3933,44 @@ if test -z "$CXX"; then
 do
   # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
-$as_echo_n "checking for $ac_word... " >&6; }
-if ${ac_cv_prog_ac_ct_CXX+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  if test -n "$ac_ct_CXX"; then
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+printf %s "checking for $ac_word... " >&6; }
+if test ${ac_cv_prog_ac_ct_CXX+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) if test -n "$ac_ct_CXX"; then
   ac_cv_prog_ac_ct_CXX="$ac_ct_CXX" # Let the user override the test.
 else
 as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
 for as_dir in $PATH
 do
   IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
+  case $as_dir in #(((
+    '') as_dir=./ ;;
+    */) ;;
+    *) as_dir=$as_dir/ ;;
+  esac
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+  if as_fn_executable_p "$as_dir$ac_word$ac_exec_ext"; then
     ac_cv_prog_ac_ct_CXX="$ac_prog"
-    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    printf "%s\n" "$as_me:${as_lineno-$LINENO}: found $as_dir$ac_word$ac_exec_ext" >&5
     break 2
   fi
 done
   done
 IFS=$as_save_IFS
 
-fi
+fi ;;
+esac
 fi
 ac_ct_CXX=$ac_cv_prog_ac_ct_CXX
 if test -n "$ac_ct_CXX"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_ct_CXX" >&5
-$as_echo "$ac_ct_CXX" >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_ct_CXX" >&5
+printf "%s\n" "$ac_ct_CXX" >&6; }
 else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
 fi
 
 
@@ -3374,8 +3982,8 @@ done
   else
     case $cross_compiling:$ac_tool_warned in
 yes:)
-{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
-$as_echo "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
+printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
 ac_tool_warned=yes ;;
 esac
     CXX=$ac_ct_CXX
@@ -3385,7 +3993,7 @@ fi
   fi
 fi
 # Provide some information about the compiler.
-$as_echo "$as_me:${as_lineno-$LINENO}: checking for C++ compiler version" >&5
+printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for C++ compiler version" >&5
 set X $ac_compile
 ac_compiler=$2
 for ac_option in --version -v -V -qversion; do
@@ -3395,7 +4003,7 @@ case "(($ac_try" in
   *) ac_try_echo=$ac_try;;
 esac
 eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
-$as_echo "$ac_try_echo"; } >&5
+printf "%s\n" "$ac_try_echo"; } >&5
   (eval "$ac_compiler $ac_option >&5") 2>conftest.err
   ac_status=$?
   if test -s conftest.err; then
@@ -3405,7 +4013,7 @@ $as_echo "$ac_try_echo"; } >&5
     cat conftest.er1 >&5
   fi
   rm -f conftest.er1 conftest.err
-  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
   test $ac_status = 0; }
 done
 
@@ -3413,7 +4021,7 @@ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
@@ -3425,9 +4033,9 @@ ac_clean_files="$ac_clean_files a.out a.out.dSYM a.exe b.out"
 # Try to create an executable without -o first, disregard a.out.
 # It will help us diagnose broken compilers, and finding out an intuition
 # of exeext.
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the C++ compiler works" >&5
-$as_echo_n "checking whether the C++ compiler works... " >&6; }
-ac_link_default=`$as_echo "$ac_link" | sed 's/ -o *conftest[^ ]*//'`
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether the C++ compiler works" >&5
+printf %s "checking whether the C++ compiler works... " >&6; }
+ac_link_default=`printf "%s\n" "$ac_link" | sed 's/ -o *conftest[^ ]*//'`
 
 # The possible output files:
 ac_files="a.out conftest.exe conftest a.exe a_out.exe b.out conftest.*"
@@ -3448,13 +4056,14 @@ case "(($ac_try" in
   *) ac_try_echo=$ac_try;;
 esac
 eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
-$as_echo "$ac_try_echo"; } >&5
+printf "%s\n" "$ac_try_echo"; } >&5
   (eval "$ac_link_default") 2>&5
   ac_status=$?
-  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
-  test $ac_status = 0; }; then :
-  # Autoconf-2.13 could set the ac_cv_exeext variable to `no'.
-# So ignore a value of `no', otherwise this would lead to `EXEEXT = no'
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+then :
+  # Autoconf-2.13 could set the ac_cv_exeext variable to 'no'.
+# So ignore a value of 'no', otherwise this would lead to 'EXEEXT = no'
 # in a Makefile.  We should not override ac_cv_exeext if it was cached,
 # so that the user can short-circuit this test for compilers unknown to
 # Autoconf.
@@ -3469,12 +4078,12 @@ do
 	# certainly right.
 	break;;
     *.* )
-	if test "${ac_cv_exeext+set}" = set && test "$ac_cv_exeext" != no;
+	if test ${ac_cv_exeext+y} && test "$ac_cv_exeext" != no;
 	then :; else
 	   ac_cv_exeext=`expr "$ac_file" : '[^.]*\(\..*\)'`
 	fi
 	# We set ac_cv_exeext here because the later test for it is not
-	# safe: cross compilers may not add the suffix if given an `-o'
+	# safe: cross compilers may not add the suffix if given an '-o'
 	# argument, so we may need to know it at that point already.
 	# Even if this section looks crufty: it has the advantage of
 	# actually working.
@@ -3485,48 +4094,52 @@ do
 done
 test "$ac_cv_exeext" = no && ac_cv_exeext=
 
-else
-  ac_file=''
+else case e in #(
+  e) ac_file='' ;;
+esac
 fi
-if test -z "$ac_file"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-$as_echo "$as_me: failed program was:" >&5
+if test -z "$ac_file"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+printf "%s\n" "$as_me: failed program was:" >&5
 sed 's/^/| /' conftest.$ac_ext >&5
 
-{ { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
-$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+{ { printf "%s\n" "$as_me:${as_lineno-$LINENO}: error: in '$ac_pwd':" >&5
+printf "%s\n" "$as_me: error: in '$ac_pwd':" >&2;}
 as_fn_error 77 "C++ compiler cannot create executables
-See \`config.log' for more details" "$LINENO" 5; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
+See 'config.log' for more details" "$LINENO" 5; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; } ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for C++ compiler default output file name" >&5
-$as_echo_n "checking for C++ compiler default output file name... " >&6; }
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_file" >&5
-$as_echo "$ac_file" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for C++ compiler default output file name" >&5
+printf %s "checking for C++ compiler default output file name... " >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_file" >&5
+printf "%s\n" "$ac_file" >&6; }
 ac_exeext=$ac_cv_exeext
 
 rm -f -r a.out a.out.dSYM a.exe conftest$ac_cv_exeext b.out
 ac_clean_files=$ac_clean_files_save
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for suffix of executables" >&5
-$as_echo_n "checking for suffix of executables... " >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for suffix of executables" >&5
+printf %s "checking for suffix of executables... " >&6; }
 if { { ac_try="$ac_link"
 case "(($ac_try" in
   *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
   *) ac_try_echo=$ac_try;;
 esac
 eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
-$as_echo "$ac_try_echo"; } >&5
+printf "%s\n" "$ac_try_echo"; } >&5
   (eval "$ac_link") 2>&5
   ac_status=$?
-  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
-  test $ac_status = 0; }; then :
-  # If both `conftest.exe' and `conftest' are `present' (well, observable)
-# catch `conftest.exe'.  For instance with Cygwin, `ls conftest' will
-# work properly (i.e., refer to `conftest.exe'), while it won't with
-# `rm'.
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+then :
+  # If both 'conftest.exe' and 'conftest' are 'present' (well, observable)
+# catch 'conftest.exe'.  For instance with Cygwin, 'ls conftest' will
+# work properly (i.e., refer to 'conftest.exe'), while it won't with
+# 'rm'.
 for ac_file in conftest.exe conftest conftest.*; do
   test -f "$ac_file" || continue
   case $ac_file in
@@ -3536,15 +4149,16 @@ for ac_file in conftest.exe conftest conftest.*; do
     * ) break;;
   esac
 done
-else
-  { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
-$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+else case e in #(
+  e) { { printf "%s\n" "$as_me:${as_lineno-$LINENO}: error: in '$ac_pwd':" >&5
+printf "%s\n" "$as_me: error: in '$ac_pwd':" >&2;}
 as_fn_error $? "cannot compute suffix of executables: cannot compile and link
-See \`config.log' for more details" "$LINENO" 5; }
+See 'config.log' for more details" "$LINENO" 5; } ;;
+esac
 fi
 rm -f conftest conftest$ac_cv_exeext
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_exeext" >&5
-$as_echo "$ac_cv_exeext" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_exeext" >&5
+printf "%s\n" "$ac_cv_exeext" >&6; }
 
 rm -f conftest.$ac_ext
 EXEEXT=$ac_cv_exeext
@@ -3553,9 +4167,11 @@ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 #include <stdio.h>
 int
-main ()
+main (void)
 {
 FILE *f = fopen ("conftest.out", "w");
+ if (!f)
+  return 1;
  return ferror (f) || fclose (f) != 0;
 
   ;
@@ -3565,8 +4181,8 @@ _ACEOF
 ac_clean_files="$ac_clean_files conftest.out"
 # Check that the compiler produces executables we can run.  If not, either
 # the compiler is broken, or we cross compile.
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether we are cross compiling" >&5
-$as_echo_n "checking whether we are cross compiling... " >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether we are cross compiling" >&5
+printf %s "checking whether we are cross compiling... " >&6; }
 if test "$cross_compiling" != yes; then
   { { ac_try="$ac_link"
 case "(($ac_try" in
@@ -3574,10 +4190,10 @@ case "(($ac_try" in
   *) ac_try_echo=$ac_try;;
 esac
 eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
-$as_echo "$ac_try_echo"; } >&5
+printf "%s\n" "$ac_try_echo"; } >&5
   (eval "$ac_link") 2>&5
   ac_status=$?
-  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
   test $ac_status = 0; }
   if { ac_try='./conftest$ac_cv_exeext'
   { { case "(($ac_try" in
@@ -3585,39 +4201,41 @@ $as_echo "$ac_try_echo"; } >&5
   *) ac_try_echo=$ac_try;;
 esac
 eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
-$as_echo "$ac_try_echo"; } >&5
+printf "%s\n" "$ac_try_echo"; } >&5
   (eval "$ac_try") 2>&5
   ac_status=$?
-  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
   test $ac_status = 0; }; }; then
     cross_compiling=no
   else
     if test "$cross_compiling" = maybe; then
 	cross_compiling=yes
     else
-	{ { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
-$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
-as_fn_error $? "cannot run C++ compiled programs.
-If you meant to cross compile, use \`--host'.
-See \`config.log' for more details" "$LINENO" 5; }
+	{ { printf "%s\n" "$as_me:${as_lineno-$LINENO}: error: in '$ac_pwd':" >&5
+printf "%s\n" "$as_me: error: in '$ac_pwd':" >&2;}
+as_fn_error 77 "cannot run C++ compiled programs.
+If you meant to cross compile, use '--host'.
+See 'config.log' for more details" "$LINENO" 5; }
     fi
   fi
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $cross_compiling" >&5
-$as_echo "$cross_compiling" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $cross_compiling" >&5
+printf "%s\n" "$cross_compiling" >&6; }
 
-rm -f conftest.$ac_ext conftest$ac_cv_exeext conftest.out
+rm -f conftest.$ac_ext conftest$ac_cv_exeext \
+  conftest.o conftest.obj conftest.out
 ac_clean_files=$ac_clean_files_save
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for suffix of object files" >&5
-$as_echo_n "checking for suffix of object files... " >&6; }
-if ${ac_cv_objext+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for suffix of object files" >&5
+printf %s "checking for suffix of object files... " >&6; }
+if test ${ac_cv_objext+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
@@ -3631,11 +4249,12 @@ case "(($ac_try" in
   *) ac_try_echo=$ac_try;;
 esac
 eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
-$as_echo "$ac_try_echo"; } >&5
+printf "%s\n" "$ac_try_echo"; } >&5
   (eval "$ac_compile") 2>&5
   ac_status=$?
-  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
-  test $ac_status = 0; }; then :
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+then :
   for ac_file in conftest.o conftest.obj conftest.*; do
   test -f "$ac_file" || continue;
   case $ac_file in
@@ -3644,31 +4263,34 @@ $as_echo "$ac_try_echo"; } >&5
        break;;
   esac
 done
-else
-  $as_echo "$as_me: failed program was:" >&5
+else case e in #(
+  e) printf "%s\n" "$as_me: failed program was:" >&5
 sed 's/^/| /' conftest.$ac_ext >&5
 
-{ { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
-$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+{ { printf "%s\n" "$as_me:${as_lineno-$LINENO}: error: in '$ac_pwd':" >&5
+printf "%s\n" "$as_me: error: in '$ac_pwd':" >&2;}
 as_fn_error $? "cannot compute suffix of object files: cannot compile
-See \`config.log' for more details" "$LINENO" 5; }
+See 'config.log' for more details" "$LINENO" 5; } ;;
+esac
 fi
-rm -f conftest.$ac_cv_objext conftest.$ac_ext
+rm -f conftest.$ac_cv_objext conftest.$ac_ext ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_objext" >&5
-$as_echo "$ac_cv_objext" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_objext" >&5
+printf "%s\n" "$ac_cv_objext" >&6; }
 OBJEXT=$ac_cv_objext
 ac_objext=$OBJEXT
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether we are using the GNU C++ compiler" >&5
-$as_echo_n "checking whether we are using the GNU C++ compiler... " >&6; }
-if ${ac_cv_cxx_compiler_gnu+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether the compiler supports GNU C++" >&5
+printf %s "checking whether the compiler supports GNU C++... " >&6; }
+if test ${ac_cv_cxx_compiler_gnu+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 #ifndef __GNUC__
        choke me
@@ -3678,30 +4300,36 @@ main ()
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"
+then :
   ac_compiler_gnu=yes
-else
-  ac_compiler_gnu=no
+else case e in #(
+  e) ac_compiler_gnu=no ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
 ac_cv_cxx_compiler_gnu=$ac_compiler_gnu
-
+ ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_cxx_compiler_gnu" >&5
-$as_echo "$ac_cv_cxx_compiler_gnu" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_cxx_compiler_gnu" >&5
+printf "%s\n" "$ac_cv_cxx_compiler_gnu" >&6; }
+ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
+
 if test $ac_compiler_gnu = yes; then
   GXX=yes
 else
   GXX=
 fi
-ac_test_CXXFLAGS=${CXXFLAGS+set}
+ac_test_CXXFLAGS=${CXXFLAGS+y}
 ac_save_CXXFLAGS=$CXXFLAGS
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -g" >&5
-$as_echo_n "checking whether $CXX accepts -g... " >&6; }
-if ${ac_cv_prog_cxx_g+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_save_cxx_werror_flag=$ac_cxx_werror_flag
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -g" >&5
+printf %s "checking whether $CXX accepts -g... " >&6; }
+if test ${ac_cv_prog_cxx_g+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_save_cxx_werror_flag=$ac_cxx_werror_flag
    ac_cxx_werror_flag=yes
    ac_cv_prog_cxx_g=no
    CXXFLAGS="-g"
@@ -3709,57 +4337,63 @@ else
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"
+then :
   ac_cv_prog_cxx_g=yes
-else
-  CXXFLAGS=""
+else case e in #(
+  e) CXXFLAGS=""
       cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"
+then :
 
-else
-  ac_cxx_werror_flag=$ac_save_cxx_werror_flag
+else case e in #(
+  e) ac_cxx_werror_flag=$ac_save_cxx_werror_flag
 	 CXXFLAGS="-g"
 	 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"
+then :
   ac_cv_prog_cxx_g=yes
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-   ac_cxx_werror_flag=$ac_save_cxx_werror_flag
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
+   ac_cxx_werror_flag=$ac_save_cxx_werror_flag ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_prog_cxx_g" >&5
-$as_echo "$ac_cv_prog_cxx_g" >&6; }
-if test "$ac_test_CXXFLAGS" = set; then
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_prog_cxx_g" >&5
+printf "%s\n" "$ac_cv_prog_cxx_g" >&6; }
+if test $ac_test_CXXFLAGS; then
   CXXFLAGS=$ac_save_CXXFLAGS
 elif test $ac_cv_prog_cxx_g = yes; then
   if test "$GXX" = yes; then
@@ -3774,12 +4408,121 @@ else
     CXXFLAGS=
   fi
 fi
+ac_prog_cxx_stdcxx=no
+if test x$ac_prog_cxx_stdcxx = xno
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $CXX option to enable C++11 features" >&5
+printf %s "checking for $CXX option to enable C++11 features... " >&6; }
+if test ${ac_cv_prog_cxx_cxx11+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_cv_prog_cxx_cxx11=no
+ac_save_CXX=$CXX
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+$ac_cxx_conftest_cxx11_program
+_ACEOF
+for ac_arg in '' -std=gnu++11 -std=gnu++0x -std=c++11 -std=c++0x -qlanglvl=extended0x -AA
+do
+  CXX="$ac_save_CXX $ac_arg"
+  if ac_fn_cxx_try_compile "$LINENO"
+then :
+  ac_cv_prog_cxx_cxx11=$ac_arg
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.beam
+  test "x$ac_cv_prog_cxx_cxx11" != "xno" && break
+done
+rm -f conftest.$ac_ext
+CXX=$ac_save_CXX ;;
+esac
+fi
+
+if test "x$ac_cv_prog_cxx_cxx11" = xno
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: unsupported" >&5
+printf "%s\n" "unsupported" >&6; }
+else case e in #(
+  e) if test "x$ac_cv_prog_cxx_cxx11" = x
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: none needed" >&5
+printf "%s\n" "none needed" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_prog_cxx_cxx11" >&5
+printf "%s\n" "$ac_cv_prog_cxx_cxx11" >&6; }
+     CXX="$CXX $ac_cv_prog_cxx_cxx11" ;;
+esac
+fi
+  ac_cv_prog_cxx_stdcxx=$ac_cv_prog_cxx_cxx11
+  ac_prog_cxx_stdcxx=cxx11 ;;
+esac
+fi
+fi
+if test x$ac_prog_cxx_stdcxx = xno
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $CXX option to enable C++98 features" >&5
+printf %s "checking for $CXX option to enable C++98 features... " >&6; }
+if test ${ac_cv_prog_cxx_cxx98+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_cv_prog_cxx_cxx98=no
+ac_save_CXX=$CXX
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+$ac_cxx_conftest_cxx98_program
+_ACEOF
+for ac_arg in '' -std=gnu++98 -std=c++98 -qlanglvl=extended -AA
+do
+  CXX="$ac_save_CXX $ac_arg"
+  if ac_fn_cxx_try_compile "$LINENO"
+then :
+  ac_cv_prog_cxx_cxx98=$ac_arg
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.beam
+  test "x$ac_cv_prog_cxx_cxx98" != "xno" && break
+done
+rm -f conftest.$ac_ext
+CXX=$ac_save_CXX ;;
+esac
+fi
+
+if test "x$ac_cv_prog_cxx_cxx98" = xno
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: unsupported" >&5
+printf "%s\n" "unsupported" >&6; }
+else case e in #(
+  e) if test "x$ac_cv_prog_cxx_cxx98" = x
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: none needed" >&5
+printf "%s\n" "none needed" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_prog_cxx_cxx98" >&5
+printf "%s\n" "$ac_cv_prog_cxx_cxx98" >&6; }
+     CXX="$CXX $ac_cv_prog_cxx_cxx98" ;;
+esac
+fi
+  ac_cv_prog_cxx_stdcxx=$ac_cv_prog_cxx_cxx98
+  ac_prog_cxx_stdcxx=cxx98 ;;
+esac
+fi
+fi
+
 ac_ext=c
 ac_cpp='$CPP $CPPFLAGS'
 ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
 ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
 ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
+
+
+
+
+
+
+
+
+
 ac_ext=c
 ac_cpp='$CPP $CPPFLAGS'
 ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
@@ -3790,38 +4533,44 @@ if test -n "$ac_tool_prefix"; then
   do
     # Extract the first word of "$ac_tool_prefix$ac_prog", so it can be a program name with args.
 set dummy $ac_tool_prefix$ac_prog; ac_word=$2
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
-$as_echo_n "checking for $ac_word... " >&6; }
-if ${ac_cv_prog_CC+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  if test -n "$CC"; then
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+printf %s "checking for $ac_word... " >&6; }
+if test ${ac_cv_prog_CC+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) if test -n "$CC"; then
   ac_cv_prog_CC="$CC" # Let the user override the test.
 else
 as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
 for as_dir in $PATH
 do
   IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
+  case $as_dir in #(((
+    '') as_dir=./ ;;
+    */) ;;
+    *) as_dir=$as_dir/ ;;
+  esac
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+  if as_fn_executable_p "$as_dir$ac_word$ac_exec_ext"; then
     ac_cv_prog_CC="$ac_tool_prefix$ac_prog"
-    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    printf "%s\n" "$as_me:${as_lineno-$LINENO}: found $as_dir$ac_word$ac_exec_ext" >&5
     break 2
   fi
 done
   done
 IFS=$as_save_IFS
 
-fi
+fi ;;
+esac
 fi
 CC=$ac_cv_prog_CC
 if test -n "$CC"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $CC" >&5
-$as_echo "$CC" >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $CC" >&5
+printf "%s\n" "$CC" >&6; }
 else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
 fi
 
 
@@ -3834,38 +4583,44 @@ if test -z "$CC"; then
 do
   # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
-$as_echo_n "checking for $ac_word... " >&6; }
-if ${ac_cv_prog_ac_ct_CC+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  if test -n "$ac_ct_CC"; then
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+printf %s "checking for $ac_word... " >&6; }
+if test ${ac_cv_prog_ac_ct_CC+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) if test -n "$ac_ct_CC"; then
   ac_cv_prog_ac_ct_CC="$ac_ct_CC" # Let the user override the test.
 else
 as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
 for as_dir in $PATH
 do
   IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
+  case $as_dir in #(((
+    '') as_dir=./ ;;
+    */) ;;
+    *) as_dir=$as_dir/ ;;
+  esac
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+  if as_fn_executable_p "$as_dir$ac_word$ac_exec_ext"; then
     ac_cv_prog_ac_ct_CC="$ac_prog"
-    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    printf "%s\n" "$as_me:${as_lineno-$LINENO}: found $as_dir$ac_word$ac_exec_ext" >&5
     break 2
   fi
 done
   done
 IFS=$as_save_IFS
 
-fi
+fi ;;
+esac
 fi
 ac_ct_CC=$ac_cv_prog_ac_ct_CC
 if test -n "$ac_ct_CC"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_ct_CC" >&5
-$as_echo "$ac_ct_CC" >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_ct_CC" >&5
+printf "%s\n" "$ac_ct_CC" >&6; }
 else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
 fi
 
 
@@ -3877,8 +4632,8 @@ done
   else
     case $cross_compiling:$ac_tool_warned in
 yes:)
-{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
-$as_echo "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
+printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
 ac_tool_warned=yes ;;
 esac
     CC=$ac_ct_CC
@@ -3886,23 +4641,23 @@ esac
 fi
 
 
-test -z "$CC" && { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
-$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+test -z "$CC" && { { printf "%s\n" "$as_me:${as_lineno-$LINENO}: error: in '$ac_pwd':" >&5
+printf "%s\n" "$as_me: error: in '$ac_pwd':" >&2;}
 as_fn_error $? "no acceptable C compiler found in \$PATH
-See \`config.log' for more details" "$LINENO" 5; }
+See 'config.log' for more details" "$LINENO" 5; }
 
 # Provide some information about the compiler.
-$as_echo "$as_me:${as_lineno-$LINENO}: checking for C compiler version" >&5
+printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for C compiler version" >&5
 set X $ac_compile
 ac_compiler=$2
-for ac_option in --version -v -V -qversion; do
+for ac_option in --version -v -V -qversion -version; do
   { { ac_try="$ac_compiler $ac_option >&5"
 case "(($ac_try" in
   *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
   *) ac_try_echo=$ac_try;;
 esac
 eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
-$as_echo "$ac_try_echo"; } >&5
+printf "%s\n" "$ac_try_echo"; } >&5
   (eval "$ac_compiler $ac_option >&5") 2>conftest.err
   ac_status=$?
   if test -s conftest.err; then
@@ -3912,20 +4667,21 @@ $as_echo "$ac_try_echo"; } >&5
     cat conftest.er1 >&5
   fi
   rm -f conftest.er1 conftest.err
-  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
   test $ac_status = 0; }
 done
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether we are using the GNU C compiler" >&5
-$as_echo_n "checking whether we are using the GNU C compiler... " >&6; }
-if ${ac_cv_c_compiler_gnu+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether the compiler supports GNU C" >&5
+printf %s "checking whether the compiler supports GNU C... " >&6; }
+if test ${ac_cv_c_compiler_gnu+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 #ifndef __GNUC__
        choke me
@@ -3935,30 +4691,36 @@ main ()
   return 0;
 }
 _ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
+if ac_fn_c_try_compile "$LINENO"
+then :
   ac_compiler_gnu=yes
-else
-  ac_compiler_gnu=no
+else case e in #(
+  e) ac_compiler_gnu=no ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
 ac_cv_c_compiler_gnu=$ac_compiler_gnu
-
+ ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_c_compiler_gnu" >&5
-$as_echo "$ac_cv_c_compiler_gnu" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_c_compiler_gnu" >&5
+printf "%s\n" "$ac_cv_c_compiler_gnu" >&6; }
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
 if test $ac_compiler_gnu = yes; then
   GCC=yes
 else
   GCC=
 fi
-ac_test_CFLAGS=${CFLAGS+set}
+ac_test_CFLAGS=${CFLAGS+y}
 ac_save_CFLAGS=$CFLAGS
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CC accepts -g" >&5
-$as_echo_n "checking whether $CC accepts -g... " >&6; }
-if ${ac_cv_prog_cc_g+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_save_c_werror_flag=$ac_c_werror_flag
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CC accepts -g" >&5
+printf %s "checking whether $CC accepts -g... " >&6; }
+if test ${ac_cv_prog_cc_g+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_save_c_werror_flag=$ac_c_werror_flag
    ac_c_werror_flag=yes
    ac_cv_prog_cc_g=no
    CFLAGS="-g"
@@ -3966,57 +4728,63 @@ else
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
+if ac_fn_c_try_compile "$LINENO"
+then :
   ac_cv_prog_cc_g=yes
-else
-  CFLAGS=""
+else case e in #(
+  e) CFLAGS=""
       cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
+if ac_fn_c_try_compile "$LINENO"
+then :
 
-else
-  ac_c_werror_flag=$ac_save_c_werror_flag
+else case e in #(
+  e) ac_c_werror_flag=$ac_save_c_werror_flag
 	 CFLAGS="-g"
 	 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
+if ac_fn_c_try_compile "$LINENO"
+then :
   ac_cv_prog_cc_g=yes
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-   ac_c_werror_flag=$ac_save_c_werror_flag
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
+   ac_c_werror_flag=$ac_save_c_werror_flag ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_prog_cc_g" >&5
-$as_echo "$ac_cv_prog_cc_g" >&6; }
-if test "$ac_test_CFLAGS" = set; then
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_prog_cc_g" >&5
+printf "%s\n" "$ac_cv_prog_cc_g" >&6; }
+if test $ac_test_CFLAGS; then
   CFLAGS=$ac_save_CFLAGS
 elif test $ac_cv_prog_cc_g = yes; then
   if test "$GCC" = yes; then
@@ -4031,94 +4799,153 @@ else
     CFLAGS=
   fi
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $CC option to accept ISO C89" >&5
-$as_echo_n "checking for $CC option to accept ISO C89... " >&6; }
-if ${ac_cv_prog_cc_c89+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_cv_prog_cc_c89=no
+ac_prog_cc_stdc=no
+if test x$ac_prog_cc_stdc = xno
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $CC option to enable C11 features" >&5
+printf %s "checking for $CC option to enable C11 features... " >&6; }
+if test ${ac_cv_prog_cc_c11+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_cv_prog_cc_c11=no
 ac_save_CC=$CC
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
-#include <stdarg.h>
-#include <stdio.h>
-struct stat;
-/* Most of the following tests are stolen from RCS 5.7's src/conf.sh.  */
-struct buf { int x; };
-FILE * (*rcsopen) (struct buf *, struct stat *, int);
-static char *e (p, i)
-     char **p;
-     int i;
-{
-  return p[i];
-}
-static char *f (char * (*g) (char **, int), char **p, ...)
-{
-  char *s;
-  va_list v;
-  va_start (v,p);
-  s = g (p, va_arg (v,int));
-  va_end (v);
-  return s;
-}
-
-/* OSF 4.0 Compaq cc is some sort of almost-ANSI by default.  It has
-   function prototypes and stuff, but not '\xHH' hex character constants.
-   These don't provoke an error unfortunately, instead are silently treated
-   as 'x'.  The following induces an error, until -std is added to get
-   proper ANSI mode.  Curiously '\x00'!='x' always comes out true, for an
-   array size at least.  It's necessary to write '\x00'==0 to get something
-   that's true only with -std.  */
-int osf4_cc_array ['\x00' == 0 ? 1 : -1];
+$ac_c_conftest_c11_program
+_ACEOF
+for ac_arg in '' -std=gnu11
+do
+  CC="$ac_save_CC $ac_arg"
+  if ac_fn_c_try_compile "$LINENO"
+then :
+  ac_cv_prog_cc_c11=$ac_arg
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.beam
+  test "x$ac_cv_prog_cc_c11" != "xno" && break
+done
+rm -f conftest.$ac_ext
+CC=$ac_save_CC ;;
+esac
+fi
 
-/* IBM C 6 for AIX is almost-ANSI by default, but it replaces macro parameters
-   inside strings and character constants.  */
-#define FOO(x) 'x'
-int xlc6_cc_array[FOO(a) == 'x' ? 1 : -1];
+if test "x$ac_cv_prog_cc_c11" = xno
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: unsupported" >&5
+printf "%s\n" "unsupported" >&6; }
+else case e in #(
+  e) if test "x$ac_cv_prog_cc_c11" = x
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: none needed" >&5
+printf "%s\n" "none needed" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_prog_cc_c11" >&5
+printf "%s\n" "$ac_cv_prog_cc_c11" >&6; }
+     CC="$CC $ac_cv_prog_cc_c11" ;;
+esac
+fi
+  ac_cv_prog_cc_stdc=$ac_cv_prog_cc_c11
+  ac_prog_cc_stdc=c11 ;;
+esac
+fi
+fi
+if test x$ac_prog_cc_stdc = xno
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $CC option to enable C99 features" >&5
+printf %s "checking for $CC option to enable C99 features... " >&6; }
+if test ${ac_cv_prog_cc_c99+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_cv_prog_cc_c99=no
+ac_save_CC=$CC
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+$ac_c_conftest_c99_program
+_ACEOF
+for ac_arg in '' -std=gnu99 -std=c99 -c99 -qlanglvl=extc1x -qlanglvl=extc99 -AC99 -D_STDC_C99=
+do
+  CC="$ac_save_CC $ac_arg"
+  if ac_fn_c_try_compile "$LINENO"
+then :
+  ac_cv_prog_cc_c99=$ac_arg
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.beam
+  test "x$ac_cv_prog_cc_c99" != "xno" && break
+done
+rm -f conftest.$ac_ext
+CC=$ac_save_CC ;;
+esac
+fi
 
-int test (int i, double x);
-struct s1 {int (*f) (int a);};
-struct s2 {int (*f) (double a);};
-int pairnames (int, char **, FILE *(*)(struct buf *, struct stat *, int), int, int);
-int argc;
-char **argv;
-int
-main ()
-{
-return f (e, argv, 0) != argv[0]  ||  f (e, argv, 1) != argv[1];
-  ;
-  return 0;
-}
+if test "x$ac_cv_prog_cc_c99" = xno
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: unsupported" >&5
+printf "%s\n" "unsupported" >&6; }
+else case e in #(
+  e) if test "x$ac_cv_prog_cc_c99" = x
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: none needed" >&5
+printf "%s\n" "none needed" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_prog_cc_c99" >&5
+printf "%s\n" "$ac_cv_prog_cc_c99" >&6; }
+     CC="$CC $ac_cv_prog_cc_c99" ;;
+esac
+fi
+  ac_cv_prog_cc_stdc=$ac_cv_prog_cc_c99
+  ac_prog_cc_stdc=c99 ;;
+esac
+fi
+fi
+if test x$ac_prog_cc_stdc = xno
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $CC option to enable C89 features" >&5
+printf %s "checking for $CC option to enable C89 features... " >&6; }
+if test ${ac_cv_prog_cc_c89+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_cv_prog_cc_c89=no
+ac_save_CC=$CC
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+$ac_c_conftest_c89_program
 _ACEOF
-for ac_arg in '' -qlanglvl=extc89 -qlanglvl=ansi -std \
-	-Ae "-Aa -D_HPUX_SOURCE" "-Xc -D__EXTENSIONS__"
+for ac_arg in '' -qlanglvl=extc89 -qlanglvl=ansi -std -Ae "-Aa -D_HPUX_SOURCE" "-Xc -D__EXTENSIONS__"
 do
   CC="$ac_save_CC $ac_arg"
-  if ac_fn_c_try_compile "$LINENO"; then :
+  if ac_fn_c_try_compile "$LINENO"
+then :
   ac_cv_prog_cc_c89=$ac_arg
 fi
-rm -f core conftest.err conftest.$ac_objext
+rm -f core conftest.err conftest.$ac_objext conftest.beam
   test "x$ac_cv_prog_cc_c89" != "xno" && break
 done
 rm -f conftest.$ac_ext
-CC=$ac_save_CC
+CC=$ac_save_CC ;;
+esac
+fi
 
+if test "x$ac_cv_prog_cc_c89" = xno
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: unsupported" >&5
+printf "%s\n" "unsupported" >&6; }
+else case e in #(
+  e) if test "x$ac_cv_prog_cc_c89" = x
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: none needed" >&5
+printf "%s\n" "none needed" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_prog_cc_c89" >&5
+printf "%s\n" "$ac_cv_prog_cc_c89" >&6; }
+     CC="$CC $ac_cv_prog_cc_c89" ;;
+esac
 fi
-# AC_CACHE_VAL
-case "x$ac_cv_prog_cc_c89" in
-  x)
-    { $as_echo "$as_me:${as_lineno-$LINENO}: result: none needed" >&5
-$as_echo "none needed" >&6; } ;;
-  xno)
-    { $as_echo "$as_me:${as_lineno-$LINENO}: result: unsupported" >&5
-$as_echo "unsupported" >&6; } ;;
-  *)
-    CC="$CC $ac_cv_prog_cc_c89"
-    { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_prog_cc_c89" >&5
-$as_echo "$ac_cv_prog_cc_c89" >&6; } ;;
+  ac_cv_prog_cc_stdc=$ac_cv_prog_cc_c89
+  ac_prog_cc_stdc=c89 ;;
 esac
-if test "x$ac_cv_prog_cc_c89" != xno; then :
-
+fi
 fi
 
 ac_ext=c
@@ -4141,38 +4968,44 @@ if test -n "$ac_tool_prefix"; then
   do
     # Extract the first word of "$ac_tool_prefix$ac_prog", so it can be a program name with args.
 set dummy $ac_tool_prefix$ac_prog; ac_word=$2
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
-$as_echo_n "checking for $ac_word... " >&6; }
-if ${ac_cv_prog_FC+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  if test -n "$FC"; then
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+printf %s "checking for $ac_word... " >&6; }
+if test ${ac_cv_prog_FC+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) if test -n "$FC"; then
   ac_cv_prog_FC="$FC" # Let the user override the test.
 else
 as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
 for as_dir in $PATH
 do
   IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
+  case $as_dir in #(((
+    '') as_dir=./ ;;
+    */) ;;
+    *) as_dir=$as_dir/ ;;
+  esac
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+  if as_fn_executable_p "$as_dir$ac_word$ac_exec_ext"; then
     ac_cv_prog_FC="$ac_tool_prefix$ac_prog"
-    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    printf "%s\n" "$as_me:${as_lineno-$LINENO}: found $as_dir$ac_word$ac_exec_ext" >&5
     break 2
   fi
 done
   done
 IFS=$as_save_IFS
 
-fi
+fi ;;
+esac
 fi
 FC=$ac_cv_prog_FC
 if test -n "$FC"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $FC" >&5
-$as_echo "$FC" >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $FC" >&5
+printf "%s\n" "$FC" >&6; }
 else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
 fi
 
 
@@ -4185,38 +5018,44 @@ if test -z "$FC"; then
 do
   # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
-$as_echo_n "checking for $ac_word... " >&6; }
-if ${ac_cv_prog_ac_ct_FC+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  if test -n "$ac_ct_FC"; then
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+printf %s "checking for $ac_word... " >&6; }
+if test ${ac_cv_prog_ac_ct_FC+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) if test -n "$ac_ct_FC"; then
   ac_cv_prog_ac_ct_FC="$ac_ct_FC" # Let the user override the test.
 else
 as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
 for as_dir in $PATH
 do
   IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
+  case $as_dir in #(((
+    '') as_dir=./ ;;
+    */) ;;
+    *) as_dir=$as_dir/ ;;
+  esac
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+  if as_fn_executable_p "$as_dir$ac_word$ac_exec_ext"; then
     ac_cv_prog_ac_ct_FC="$ac_prog"
-    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    printf "%s\n" "$as_me:${as_lineno-$LINENO}: found $as_dir$ac_word$ac_exec_ext" >&5
     break 2
   fi
 done
   done
 IFS=$as_save_IFS
 
-fi
+fi ;;
+esac
 fi
 ac_ct_FC=$ac_cv_prog_ac_ct_FC
 if test -n "$ac_ct_FC"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_ct_FC" >&5
-$as_echo "$ac_ct_FC" >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_ct_FC" >&5
+printf "%s\n" "$ac_ct_FC" >&6; }
 else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
 fi
 
 
@@ -4228,8 +5067,8 @@ done
   else
     case $cross_compiling:$ac_tool_warned in
 yes:)
-{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
-$as_echo "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
+printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
 ac_tool_warned=yes ;;
 esac
     FC=$ac_ct_FC
@@ -4238,7 +5077,7 @@ fi
 
 
 # Provide some information about the compiler.
-$as_echo "$as_me:${as_lineno-$LINENO}: checking for Fortran compiler version" >&5
+printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for Fortran compiler version" >&5
 set X $ac_compile
 ac_compiler=$2
 for ac_option in --version -v -V -qversion; do
@@ -4248,7 +5087,7 @@ case "(($ac_try" in
   *) ac_try_echo=$ac_try;;
 esac
 eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
-$as_echo "$ac_try_echo"; } >&5
+printf "%s\n" "$ac_try_echo"; } >&5
   (eval "$ac_compiler $ac_option >&5") 2>conftest.err
   ac_status=$?
   if test -s conftest.err; then
@@ -4258,21 +5097,22 @@ $as_echo "$ac_try_echo"; } >&5
     cat conftest.er1 >&5
   fi
   rm -f conftest.er1 conftest.err
-  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
   test $ac_status = 0; }
 done
 rm -f a.out
 
-# If we don't use `.F' as extension, the preprocessor is not run on the
+# If we don't use '.F' as extension, the preprocessor is not run on the
 # input file.  (Note that this only needs to work for GNU compilers.)
 ac_save_ext=$ac_ext
 ac_ext=F
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether we are using the GNU Fortran compiler" >&5
-$as_echo_n "checking whether we are using the GNU Fortran compiler... " >&6; }
-if ${ac_cv_fc_compiler_gnu+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  cat > conftest.$ac_ext <<_ACEOF
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether the compiler supports GNU Fortran" >&5
+printf %s "checking whether the compiler supports GNU Fortran... " >&6; }
+if test ${ac_cv_fc_compiler_gnu+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) cat > conftest.$ac_ext <<_ACEOF
       program main
 #ifndef __GNUC__
        choke me
@@ -4280,43 +5120,52 @@ else
 
       end
 _ACEOF
-if ac_fn_fc_try_compile "$LINENO"; then :
+if ac_fn_fc_try_compile "$LINENO"
+then :
   ac_compiler_gnu=yes
-else
-  ac_compiler_gnu=no
+else case e in #(
+  e) ac_compiler_gnu=no ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
 ac_cv_fc_compiler_gnu=$ac_compiler_gnu
-
+ ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_fc_compiler_gnu" >&5
-$as_echo "$ac_cv_fc_compiler_gnu" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_fc_compiler_gnu" >&5
+printf "%s\n" "$ac_cv_fc_compiler_gnu" >&6; }
+ac_compiler_gnu=$ac_cv_fc_compiler_gnu
+
 ac_ext=$ac_save_ext
-ac_test_FCFLAGS=${FCFLAGS+set}
+ac_test_FCFLAGS=${FCFLAGS+y}
 ac_save_FCFLAGS=$FCFLAGS
 FCFLAGS=
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $FC accepts -g" >&5
-$as_echo_n "checking whether $FC accepts -g... " >&6; }
-if ${ac_cv_prog_fc_g+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  FCFLAGS=-g
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $FC accepts -g" >&5
+printf %s "checking whether $FC accepts -g... " >&6; }
+if test ${ac_cv_prog_fc_g+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) FCFLAGS=-g
 cat > conftest.$ac_ext <<_ACEOF
       program main
 
       end
 _ACEOF
-if ac_fn_fc_try_compile "$LINENO"; then :
+if ac_fn_fc_try_compile "$LINENO"
+then :
   ac_cv_prog_fc_g=yes
-else
-  ac_cv_prog_fc_g=no
+else case e in #(
+  e) ac_cv_prog_fc_g=no ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
+ ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_prog_fc_g" >&5
-$as_echo "$ac_cv_prog_fc_g" >&6; }
-if test "$ac_test_FCFLAGS" = set; then
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_prog_fc_g" >&5
+printf "%s\n" "$ac_cv_prog_fc_g" >&6; }
+if test $ac_test_FCFLAGS; then
   FCFLAGS=$ac_save_FCFLAGS
 elif test $ac_cv_prog_fc_g = yes; then
   if test "x$ac_cv_fc_compiler_gnu" = xyes; then
@@ -4356,26 +5205,26 @@ if test -z "$LDSHARED" ; then
   LDSHARED="$CXX"
 fi
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: Initial CXX:         $CXX" >&5
-$as_echo "$as_me: Initial CXX:         $CXX" >&6;}
-{ $as_echo "$as_me:${as_lineno-$LINENO}: Initial CXXFLAGS:    $CXXFLAGS" >&5
-$as_echo "$as_me: Initial CXXFLAGS:    $CXXFLAGS" >&6;}
-{ $as_echo "$as_me:${as_lineno-$LINENO}: Initial CPPFLAGS:    $CPPFLAGS" >&5
-$as_echo "$as_me: Initial CPPFLAGS:    $CPPFLAGS" >&6;}
-{ $as_echo "$as_me:${as_lineno-$LINENO}: Initial CFLAGS:      $CFLAGS" >&5
-$as_echo "$as_me: Initial CFLAGS:      $CFLAGS" >&6;}
-{ $as_echo "$as_me:${as_lineno-$LINENO}: Initial LDFLAGS:     $LDFLAGS" >&5
-$as_echo "$as_me: Initial LDFLAGS:     $LDFLAGS" >&6;}
-{ $as_echo "$as_me:${as_lineno-$LINENO}: Initial LIBS:        $LIBS" >&5
-$as_echo "$as_me: Initial LIBS:        $LIBS" >&6;}
-{ $as_echo "$as_me:${as_lineno-$LINENO}: Initial STATIC_LIBS: $STATIC_LIBS" >&5
-$as_echo "$as_me: Initial STATIC_LIBS: $STATIC_LIBS" >&6;}
-{ $as_echo "$as_me:${as_lineno-$LINENO}: Initial LD:          $LD" >&5
-$as_echo "$as_me: Initial LD:          $LD" >&6;}
-{ $as_echo "$as_me:${as_lineno-$LINENO}: Initial LDSHARED:    $LDSHARED" >&5
-$as_echo "$as_me: Initial LDSHARED:    $LDSHARED" >&6;}
-{ $as_echo "$as_me:${as_lineno-$LINENO}: Initial SOEXT:       $SOEXT" >&5
-$as_echo "$as_me: Initial SOEXT:       $SOEXT" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: Initial CXX:         $CXX" >&5
+printf "%s\n" "$as_me: Initial CXX:         $CXX" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: Initial CXXFLAGS:    $CXXFLAGS" >&5
+printf "%s\n" "$as_me: Initial CXXFLAGS:    $CXXFLAGS" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: Initial CPPFLAGS:    $CPPFLAGS" >&5
+printf "%s\n" "$as_me: Initial CPPFLAGS:    $CPPFLAGS" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: Initial CFLAGS:      $CFLAGS" >&5
+printf "%s\n" "$as_me: Initial CFLAGS:      $CFLAGS" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: Initial LDFLAGS:     $LDFLAGS" >&5
+printf "%s\n" "$as_me: Initial LDFLAGS:     $LDFLAGS" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: Initial LIBS:        $LIBS" >&5
+printf "%s\n" "$as_me: Initial LIBS:        $LIBS" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: Initial STATIC_LIBS: $STATIC_LIBS" >&5
+printf "%s\n" "$as_me: Initial STATIC_LIBS: $STATIC_LIBS" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: Initial LD:          $LD" >&5
+printf "%s\n" "$as_me: Initial LD:          $LD" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: Initial LDSHARED:    $LDSHARED" >&5
+printf "%s\n" "$as_me: Initial LDSHARED:    $LDSHARED" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: Initial SOEXT:       $SOEXT" >&5
+printf "%s\n" "$as_me: Initial SOEXT:       $SOEXT" >&6;}
 
 # check C++ flags
 if test $shared = true
@@ -4384,48 +5233,52 @@ then
 
   save_CXXFLAGS="$CXXFLAGS"
   CXXFLAGS="$CXXFLAGS -fPIC"
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -fPIC" >&5
-$as_echo_n "checking whether $CXX accepts -fPIC... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -fPIC" >&5
+printf %s "checking whether $CXX accepts -fPIC... " >&6; }
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"
+then :
 
       cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
-$as_echo "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+if ac_fn_cxx_try_link "$LINENO"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
+printf "%s\n" "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS" ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
-
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+   ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
 
 
 
@@ -4437,48 +5290,52 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
   save_CFLAGS="$CFLAGS"
   CFLAGS="$CFLAGS -fPIC"
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CC accepts -fPIC" >&5
-$as_echo_n "checking whether $CC accepts -fPIC... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CC accepts -fPIC" >&5
+printf %s "checking whether $CC accepts -fPIC... " >&6; }
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
+if ac_fn_c_try_compile "$LINENO"
+then :
 
       cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
-$as_echo "not linking" >&6; }; CCFLAGS="$save_CCFLAGS"
+if ac_fn_c_try_link "$LINENO"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
+printf "%s\n" "not linking" >&6; }; CCFLAGS="$save_CCFLAGS" ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }; CCFLAGS="$save_CCFLAGS"
-
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }; CCFLAGS="$save_CCFLAGS"
+   ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
   ac_ext=cpp
 ac_cpp='$CXXCPP $CPPFLAGS'
 ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
@@ -4493,94 +5350,102 @@ then
 
   save_CXXFLAGS="$CXXFLAGS"
   CXXFLAGS="$CXXFLAGS -Wall"
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -Wall" >&5
-$as_echo_n "checking whether $CXX accepts -Wall... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -Wall" >&5
+printf %s "checking whether $CXX accepts -Wall... " >&6; }
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"
+then :
 
       cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
-$as_echo "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+if ac_fn_cxx_try_link "$LINENO"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
+printf "%s\n" "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS" ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
-
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+   ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
 
 
   save_CXXFLAGS="$CXXFLAGS"
   CXXFLAGS="$CXXFLAGS -pedantic"
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -pedantic" >&5
-$as_echo_n "checking whether $CXX accepts -pedantic... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -pedantic" >&5
+printf %s "checking whether $CXX accepts -pedantic... " >&6; }
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"
+then :
 
       cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
-$as_echo "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+if ac_fn_cxx_try_link "$LINENO"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
+printf "%s\n" "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS" ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
-
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+   ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
 
 fi
 
@@ -4589,48 +5454,52 @@ then
 
   save_CXXFLAGS="$CXXFLAGS"
   CXXFLAGS="$CXXFLAGS -std=c++$cxx_level"
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -std=c++$cxx_level" >&5
-$as_echo_n "checking whether $CXX accepts -std=c++$cxx_level... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -std=c++$cxx_level" >&5
+printf %s "checking whether $CXX accepts -std=c++$cxx_level... " >&6; }
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"
+then :
 
       cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
-$as_echo "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+if ac_fn_cxx_try_link "$LINENO"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
+printf "%s\n" "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS" ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
-
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+   ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
 
 fi
 
@@ -4639,48 +5508,52 @@ then
 
   save_CXXFLAGS="$CXXFLAGS"
   CXXFLAGS="$CXXFLAGS -g"
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -g" >&5
-$as_echo_n "checking whether $CXX accepts -g... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -g" >&5
+printf %s "checking whether $CXX accepts -g... " >&6; }
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"
+then :
 
       cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
-$as_echo "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+if ac_fn_cxx_try_link "$LINENO"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
+printf "%s\n" "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS" ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
-
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+   ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
 
 fi
 
@@ -4692,27 +5565,29 @@ then
 
   save_LDFLAGS="$LDFLAGS"
   LDFLAGS="$LDFLAGS --coverage"
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether LDFLAGS can contain --coverage" >&5
-$as_echo_n "checking whether LDFLAGS can contain --coverage... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether LDFLAGS can contain --coverage" >&5
+printf %s "checking whether LDFLAGS can contain --coverage... " >&6; }
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }; LDFLAGS="$save_LDFLAGS"
+if ac_fn_cxx_try_link "$LINENO"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }; LDFLAGS="$save_LDFLAGS" ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
   STATIC_LIBS="$STATIC_LIBS --coverage"
@@ -4723,467 +5598,507 @@ then
 
   save_CXXFLAGS="$CXXFLAGS"
   CXXFLAGS="$CXXFLAGS -Wextra"
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -Wextra" >&5
-$as_echo_n "checking whether $CXX accepts -Wextra... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -Wextra" >&5
+printf %s "checking whether $CXX accepts -Wextra... " >&6; }
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"
+then :
 
       cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
-$as_echo "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+if ac_fn_cxx_try_link "$LINENO"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
+printf "%s\n" "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS" ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
-
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+   ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
 
 
   save_CXXFLAGS="$CXXFLAGS"
   CXXFLAGS="$CXXFLAGS -Wfloat-equal"
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -Wfloat-equal" >&5
-$as_echo_n "checking whether $CXX accepts -Wfloat-equal... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -Wfloat-equal" >&5
+printf %s "checking whether $CXX accepts -Wfloat-equal... " >&6; }
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"
+then :
 
       cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
-$as_echo "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+if ac_fn_cxx_try_link "$LINENO"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
+printf "%s\n" "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS" ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
-
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+   ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
 
 
   save_CXXFLAGS="$CXXFLAGS"
   CXXFLAGS="$CXXFLAGS -Wwrite-strings"
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -Wwrite-strings" >&5
-$as_echo_n "checking whether $CXX accepts -Wwrite-strings... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -Wwrite-strings" >&5
+printf %s "checking whether $CXX accepts -Wwrite-strings... " >&6; }
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"
+then :
 
       cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
-$as_echo "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+if ac_fn_cxx_try_link "$LINENO"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
+printf "%s\n" "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS" ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
-
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+   ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
 
 
   save_CXXFLAGS="$CXXFLAGS"
   CXXFLAGS="$CXXFLAGS -Wpointer-arith"
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -Wpointer-arith" >&5
-$as_echo_n "checking whether $CXX accepts -Wpointer-arith... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -Wpointer-arith" >&5
+printf %s "checking whether $CXX accepts -Wpointer-arith... " >&6; }
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"
+then :
 
       cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
-$as_echo "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+if ac_fn_cxx_try_link "$LINENO"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
+printf "%s\n" "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS" ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
-
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+   ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
 
 
   save_CXXFLAGS="$CXXFLAGS"
   CXXFLAGS="$CXXFLAGS -Wcast-qual"
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -Wcast-qual" >&5
-$as_echo_n "checking whether $CXX accepts -Wcast-qual... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -Wcast-qual" >&5
+printf %s "checking whether $CXX accepts -Wcast-qual... " >&6; }
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"
+then :
 
       cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
-$as_echo "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+if ac_fn_cxx_try_link "$LINENO"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
+printf "%s\n" "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS" ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
-
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+   ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
 
 
   save_CXXFLAGS="$CXXFLAGS"
   CXXFLAGS="$CXXFLAGS -Wcast-align"
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -Wcast-align" >&5
-$as_echo_n "checking whether $CXX accepts -Wcast-align... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -Wcast-align" >&5
+printf %s "checking whether $CXX accepts -Wcast-align... " >&6; }
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"
+then :
 
       cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
-$as_echo "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+if ac_fn_cxx_try_link "$LINENO"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
+printf "%s\n" "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS" ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
-
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+   ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
 
 
   save_CXXFLAGS="$CXXFLAGS"
   CXXFLAGS="$CXXFLAGS -Wconversion"
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -Wconversion" >&5
-$as_echo_n "checking whether $CXX accepts -Wconversion... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -Wconversion" >&5
+printf %s "checking whether $CXX accepts -Wconversion... " >&6; }
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"
+then :
 
       cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
-$as_echo "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+if ac_fn_cxx_try_link "$LINENO"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
+printf "%s\n" "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS" ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
-
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+   ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
 
 
   save_CXXFLAGS="$CXXFLAGS"
   CXXFLAGS="$CXXFLAGS -Wredundant-delcs"
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -Wredundant-delcs" >&5
-$as_echo_n "checking whether $CXX accepts -Wredundant-delcs... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -Wredundant-delcs" >&5
+printf %s "checking whether $CXX accepts -Wredundant-delcs... " >&6; }
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"
+then :
 
       cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
-$as_echo "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+if ac_fn_cxx_try_link "$LINENO"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
+printf "%s\n" "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS" ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
-
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+   ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
 
 
   save_CXXFLAGS="$CXXFLAGS"
   CXXFLAGS="$CXXFLAGS -Wvariadic-macros"
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -Wvariadic-macros" >&5
-$as_echo_n "checking whether $CXX accepts -Wvariadic-macros... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -Wvariadic-macros" >&5
+printf %s "checking whether $CXX accepts -Wvariadic-macros... " >&6; }
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"
+then :
 
       cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
-$as_echo "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+if ac_fn_cxx_try_link "$LINENO"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
+printf "%s\n" "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS" ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
-
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+   ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
 
 
   save_CXXFLAGS="$CXXFLAGS"
   CXXFLAGS="$CXXFLAGS -Wold-style-cast"
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -Wold-style-cast" >&5
-$as_echo_n "checking whether $CXX accepts -Wold-style-cast... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -Wold-style-cast" >&5
+printf %s "checking whether $CXX accepts -Wold-style-cast... " >&6; }
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"
+then :
 
       cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
-$as_echo "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+if ac_fn_cxx_try_link "$LINENO"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
+printf "%s\n" "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS" ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
-
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+   ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
 
 fi
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX declares c++17 support" >&5
-$as_echo_n "checking whether $CXX declares c++17 support... " >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CXX declares c++17 support" >&5
+printf %s "checking whether $CXX declares c++17 support... " >&6; }
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
@@ -5192,40 +6107,42 @@ this_compiler_does_not_support_cxx17
 #endif
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; };
+if ac_fn_cxx_try_compile "$LINENO"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; };
   support_cxx17=true
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; } ;
-  support_cxx17=false
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; } ;
+  support_cxx17=false ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
 
 if test "$support_cxx17" = false
 then
-   { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: C++17 support is required as of PLUMED 2.10" >&5
-$as_echo "$as_me: WARNING: C++17 support is required as of PLUMED 2.10" >&2;}
-   { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Your compiler appears not to support C++17" >&5
-$as_echo "$as_me: WARNING: Your compiler appears not to support C++17" >&2;}
-   { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Please change compiler or make sure that everything works correctly" >&5
-$as_echo "$as_me: WARNING: Please change compiler or make sure that everything works correctly" >&2;}
+   { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: C++17 support is required as of PLUMED 2.10" >&5
+printf "%s\n" "$as_me: WARNING: C++17 support is required as of PLUMED 2.10" >&2;}
+   { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: Your compiler appears not to support C++17" >&5
+printf "%s\n" "$as_me: WARNING: Your compiler appears not to support C++17" >&2;}
+   { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: Please change compiler or make sure that everything works correctly" >&5
+printf "%s\n" "$as_me: WARNING: Please change compiler or make sure that everything works correctly" >&2;}
 fi
 
 
 
 if test "$dependency_tracking" = true
 then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX can generate dependency file with -MM -MF" >&5
-$as_echo_n "checking whether $CXX can generate dependency file with -MM -MF... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CXX can generate dependency file with -MM -MF" >&5
+printf %s "checking whether $CXX can generate dependency file with -MM -MF... " >&6; }
   dependency=ko
   echo "#include \"conftest1.h\"" > conftest.cpp
   echo "#include \"conftest2.h\"" > conftest1.h
@@ -5233,12 +6150,12 @@ $as_echo_n "checking whether $CXX can generate dependency file with -MM -MF... "
   $CXX $CXXFLAGS -c -MM -MFconftest.d conftest.cpp 1> /dev/null 2> /dev/null
   grep conftest2 conftest.d 1> /dev/null 2>/dev/null && dependency=ok
   if test "$dependency" = ok ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
     disable_dependency_tracking=no
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
     disable_dependency_tracking=yes
   fi
 else
@@ -5246,11 +6163,11 @@ else
 fi
 
 if test "$disable_dependency_tracking" = yes ; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: dependencies tracking disabled - always make clean before make" >&5
-$as_echo "$as_me: WARNING: dependencies tracking disabled - always make clean before make" >&2;}
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: dependencies tracking disabled - always make clean before make" >&5
+printf "%s\n" "$as_me: WARNING: dependencies tracking disabled - always make clean before make" >&2;}
 else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: dependency tracking enabled" >&5
-$as_echo "$as_me: dependency tracking enabled" >&6;}
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: dependency tracking enabled" >&5
+printf "%s\n" "$as_me: dependency tracking enabled" >&6;}
 fi
 
 
@@ -5259,55 +6176,59 @@ then
 
   save_CXXFLAGS="$CXXFLAGS"
   CXXFLAGS="$CXXFLAGS -fno-gnu-unique"
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -fno-gnu-unique" >&5
-$as_echo_n "checking whether $CXX accepts -fno-gnu-unique... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -fno-gnu-unique" >&5
+printf %s "checking whether $CXX accepts -fno-gnu-unique... " >&6; }
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"
+then :
 
       cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
-$as_echo "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+if ac_fn_cxx_try_link "$LINENO"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
+printf "%s\n" "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS" ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
-
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+   ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
 
 fi
 
 #### Compulsory libraries ####
 # some of them might be made optional if we find that are not available in some system
-{ $as_echo "$as_me:${as_lineno-$LINENO}: Now we will check compulsory headers and libraries" >&5
-$as_echo "$as_me: Now we will check compulsory headers and libraries" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: Now we will check compulsory headers and libraries" >&5
+printf "%s\n" "$as_me: Now we will check compulsory headers and libraries" >&6;}
 
 
     found=ko
@@ -5332,8 +6253,8 @@ $as_echo "$as_me: Now we will check compulsory headers and libraries" >&6;}
     fi
 
     # check without libraries
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking filesystem library without extra libs" >&5
-$as_echo_n "checking filesystem library without extra libs... " >&6; }
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking filesystem library without extra libs" >&5
+printf %s "checking filesystem library without extra libs... " >&6; }
     cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
@@ -5350,22 +6271,24 @@ int main(){
 }
 
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"
+then :
   found=ok
-          { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-
+          { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+       ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
     if test "$found" = "ko" ; then
       if test "$multiple" = "yes" ; then
-        { $as_echo "$as_me:${as_lineno-$LINENO}: checking filesystem library with $all_LIBS" >&5
-$as_echo_n "checking filesystem library with $all_LIBS... " >&6; }
+        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking filesystem library with $all_LIBS" >&5
+printf %s "checking filesystem library with $all_LIBS... " >&6; }
         LIBS="$all_LIBS $LIBS"
         cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
@@ -5383,22 +6306,24 @@ int main(){
 }
 
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"
+then :
   found=ok
-              { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-
+              { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+           ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
       else
         for testlib in $testlibs
         do
-          { $as_echo "$as_me:${as_lineno-$LINENO}: checking filesystem library with -l$testlib" >&5
-$as_echo_n "checking filesystem library with -l$testlib... " >&6; }
+          { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking filesystem library with -l$testlib" >&5
+printf %s "checking filesystem library with -l$testlib... " >&6; }
           LIBS="-l$testlib $LIBS"
           cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
@@ -5416,16 +6341,18 @@ int main(){
 }
 
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"
+then :
   found=ok
-                { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-
+                { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+           ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
           if test $found = ok ; then
             break
@@ -5436,12 +6363,12 @@ rm -f core conftest.err conftest.$ac_objext \
     fi
 
     if test $found = ok ; then
-      $as_echo "#define __PLUMED_CXX17_FILESYSTEM 1" >>confdefs.h
+      printf "%s\n" "#define __PLUMED_CXX17_FILESYSTEM 1" >>confdefs.h
 
       __PLUMED_CXX17_FILESYSTEM=yes
     else
-      { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_CXX17_FILESYSTEM" >&5
-$as_echo "$as_me: WARNING: cannot enable __PLUMED_CXX17_FILESYSTEM" >&2;}
+      { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_CXX17_FILESYSTEM" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable __PLUMED_CXX17_FILESYSTEM" >&2;}
       LIBS="$save_LIBS"
     fi
 
@@ -5460,452 +6387,474 @@ lapack_found=
 # external lapack can only work with external blas
 # thus, if external blas are disabled also external lapack should be disabled
 if test "$external_blas" = false && test "$external_lapack" = true ; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: Internal blas can only be used with internal lapack" >&5
-$as_echo "$as_me: Internal blas can only be used with internal lapack" >&6;}
-  { $as_echo "$as_me:${as_lineno-$LINENO}: Will not search for external lapack" >&5
-$as_echo "$as_me: Will not search for external lapack" >&6;}
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Internal blas can only be used with internal lapack" >&5
+printf "%s\n" "$as_me: Internal blas can only be used with internal lapack" >&6;}
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Will not search for external lapack" >&5
+printf "%s\n" "$as_me: Will not search for external lapack" >&6;}
   external_lapack=false
 fi
 
 # first look for blas
 if test "$external_blas" = true ; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether dgemv_ can be linked with no library" >&5
-$as_echo_n "checking whether dgemv_ can be linked with no library... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether dgemv_ can be linked with no library" >&5
+printf %s "checking whether dgemv_ can be linked with no library... " >&6; }
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char dgemv_ ();
+namespace conftest {
+  extern "C" int dgemv_ ();
+}
 int
-main ()
+main (void)
 {
-return dgemv_ ();
+return conftest::dgemv_ ();
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"
+then :
 
-    { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
     blas_found=underscore
 
-else
-
-    { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether dgemv_ can be linked with no library" >&5
-$as_echo_n "checking whether dgemv_ can be linked with no library... " >&6; }
+else case e in #(
+  e)
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether dgemv_ can be linked with no library" >&5
+printf %s "checking whether dgemv_ can be linked with no library... " >&6; }
     cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char dgemv ();
+namespace conftest {
+  extern "C" int dgemv ();
+}
 int
-main ()
+main (void)
 {
-return dgemv ();
+return conftest::dgemv ();
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"
+then :
 
-      { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
+      { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
       blas_found=nounderscore
 
-else
-
-      { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
+else case e in #(
+  e)
+      { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
 
   if test "${libsearch}" = true ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing dgemv_" >&5
-$as_echo_n "checking for library containing dgemv_... " >&6; }
-if ${ac_cv_search_dgemv_+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing dgemv_" >&5
+printf %s "checking for library containing dgemv_... " >&6; }
+if test ${ac_cv_search_dgemv_+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char dgemv_ ();
+namespace conftest {
+  extern "C" int dgemv_ ();
+}
 int
-main ()
+main (void)
 {
-return dgemv_ ();
+return conftest::dgemv_ ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' blas; do
+for ac_lib in '' blas
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_dgemv_=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_dgemv_+:} false; then :
+  if test ${ac_cv_search_dgemv_+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_dgemv_+:} false; then :
+if test ${ac_cv_search_dgemv_+y}
+then :
 
-else
-  ac_cv_search_dgemv_=no
+else case e in #(
+  e) ac_cv_search_dgemv_=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dgemv_" >&5
-$as_echo "$ac_cv_search_dgemv_" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dgemv_" >&5
+printf "%s\n" "$ac_cv_search_dgemv_" >&6; }
 ac_res=$ac_cv_search_dgemv_
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   blas_found=underscore
-else
-
+else case e in #(
+  e)
 
   if test "${libsearch}" = true ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing dgemv" >&5
-$as_echo_n "checking for library containing dgemv... " >&6; }
-if ${ac_cv_search_dgemv+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing dgemv" >&5
+printf %s "checking for library containing dgemv... " >&6; }
+if test ${ac_cv_search_dgemv+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char dgemv ();
+namespace conftest {
+  extern "C" int dgemv ();
+}
 int
-main ()
+main (void)
 {
-return dgemv ();
+return conftest::dgemv ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' blas; do
+for ac_lib in '' blas
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_dgemv=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_dgemv+:} false; then :
+  if test ${ac_cv_search_dgemv+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_dgemv+:} false; then :
+if test ${ac_cv_search_dgemv+y}
+then :
 
-else
-  ac_cv_search_dgemv=no
+else case e in #(
+  e) ac_cv_search_dgemv=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dgemv" >&5
-$as_echo "$ac_cv_search_dgemv" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dgemv" >&5
+printf "%s\n" "$ac_cv_search_dgemv" >&6; }
 ac_res=$ac_cv_search_dgemv
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   blas_found=nounderscore
 fi
 
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing dgemv" >&5
-$as_echo_n "checking for library containing dgemv... " >&6; }
-if ${ac_cv_search_dgemv+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing dgemv" >&5
+printf %s "checking for library containing dgemv... " >&6; }
+if test ${ac_cv_search_dgemv+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char dgemv ();
+namespace conftest {
+  extern "C" int dgemv ();
+}
 int
-main ()
+main (void)
 {
-return dgemv ();
+return conftest::dgemv ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_dgemv=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_dgemv+:} false; then :
+  if test ${ac_cv_search_dgemv+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_dgemv+:} false; then :
+if test ${ac_cv_search_dgemv+y}
+then :
 
-else
-  ac_cv_search_dgemv=no
+else case e in #(
+  e) ac_cv_search_dgemv=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dgemv" >&5
-$as_echo "$ac_cv_search_dgemv" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dgemv" >&5
+printf "%s\n" "$ac_cv_search_dgemv" >&6; }
 ac_res=$ac_cv_search_dgemv
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   blas_found=nounderscore
 fi
 
   fi
 
-
+       ;;
+esac
 fi
 
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing dgemv_" >&5
-$as_echo_n "checking for library containing dgemv_... " >&6; }
-if ${ac_cv_search_dgemv_+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing dgemv_" >&5
+printf %s "checking for library containing dgemv_... " >&6; }
+if test ${ac_cv_search_dgemv_+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char dgemv_ ();
+namespace conftest {
+  extern "C" int dgemv_ ();
+}
 int
-main ()
+main (void)
 {
-return dgemv_ ();
+return conftest::dgemv_ ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_dgemv_=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_dgemv_+:} false; then :
+  if test ${ac_cv_search_dgemv_+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_dgemv_+:} false; then :
+if test ${ac_cv_search_dgemv_+y}
+then :
 
-else
-  ac_cv_search_dgemv_=no
+else case e in #(
+  e) ac_cv_search_dgemv_=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dgemv_" >&5
-$as_echo "$ac_cv_search_dgemv_" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dgemv_" >&5
+printf "%s\n" "$ac_cv_search_dgemv_" >&6; }
 ac_res=$ac_cv_search_dgemv_
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   blas_found=underscore
-else
-
+else case e in #(
+  e)
 
   if test "${libsearch}" = true ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing dgemv" >&5
-$as_echo_n "checking for library containing dgemv... " >&6; }
-if ${ac_cv_search_dgemv+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing dgemv" >&5
+printf %s "checking for library containing dgemv... " >&6; }
+if test ${ac_cv_search_dgemv+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char dgemv ();
+namespace conftest {
+  extern "C" int dgemv ();
+}
 int
-main ()
+main (void)
 {
-return dgemv ();
+return conftest::dgemv ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' blas; do
+for ac_lib in '' blas
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_dgemv=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_dgemv+:} false; then :
+  if test ${ac_cv_search_dgemv+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_dgemv+:} false; then :
+if test ${ac_cv_search_dgemv+y}
+then :
 
-else
-  ac_cv_search_dgemv=no
+else case e in #(
+  e) ac_cv_search_dgemv=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dgemv" >&5
-$as_echo "$ac_cv_search_dgemv" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dgemv" >&5
+printf "%s\n" "$ac_cv_search_dgemv" >&6; }
 ac_res=$ac_cv_search_dgemv
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   blas_found=nounderscore
 fi
 
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing dgemv" >&5
-$as_echo_n "checking for library containing dgemv... " >&6; }
-if ${ac_cv_search_dgemv+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing dgemv" >&5
+printf %s "checking for library containing dgemv... " >&6; }
+if test ${ac_cv_search_dgemv+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char dgemv ();
+namespace conftest {
+  extern "C" int dgemv ();
+}
 int
-main ()
+main (void)
 {
-return dgemv ();
+return conftest::dgemv ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_dgemv=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_dgemv+:} false; then :
+  if test ${ac_cv_search_dgemv+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_dgemv+:} false; then :
+if test ${ac_cv_search_dgemv+y}
+then :
 
-else
-  ac_cv_search_dgemv=no
+else case e in #(
+  e) ac_cv_search_dgemv=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dgemv" >&5
-$as_echo "$ac_cv_search_dgemv" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dgemv" >&5
+printf "%s\n" "$ac_cv_search_dgemv" >&6; }
 ac_res=$ac_cv_search_dgemv
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   blas_found=nounderscore
 fi
 
   fi
 
-
+       ;;
+esac
 fi
 
   fi
 
-
+     ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
-
+   ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 fi
 
 # if not found, then use internal lapack and blas
 if test -z "$blas_found" ; then
-{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: using internal lapack and blas, could be inefficient" >&5
-$as_echo "$as_me: WARNING: using internal lapack and blas, could be inefficient" >&2;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using internal lapack and blas, could be inefficient" >&5
+printf "%s\n" "$as_me: WARNING: using internal lapack and blas, could be inefficient" >&2;}
 fi
 
 # if found, also look for external lapack
 if test -n "$blas_found" ; then
 
-$as_echo "#define __PLUMED_HAS_EXTERNAL_BLAS 1" >>confdefs.h
+printf "%s\n" "#define __PLUMED_HAS_EXTERNAL_BLAS 1" >>confdefs.h
 
 
 if test "$external_lapack" = true ; then
@@ -5916,119 +6865,127 @@ case "$blas_found" in
 esac
 
   if test "${libsearch}" = true ; then
-    as_ac_Search=`$as_echo "ac_cv_search_$search_for" | $as_tr_sh`
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing $search_for" >&5
-$as_echo_n "checking for library containing $search_for... " >&6; }
-if eval \${$as_ac_Search+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    as_ac_Search=`printf "%s\n" "ac_cv_search_$search_for" | sed "$as_sed_sh"`
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing $search_for" >&5
+printf %s "checking for library containing $search_for... " >&6; }
+if eval test \${$as_ac_Search+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char $search_for ();
+namespace conftest {
+  extern "C" int $search_for ();
+}
 int
-main ()
+main (void)
 {
-return $search_for ();
+return conftest::$search_for ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' lapack; do
+for ac_lib in '' lapack
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   eval "$as_ac_Search=\$ac_res"
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if eval \${$as_ac_Search+:} false; then :
+  if eval test \${$as_ac_Search+y}
+then :
   break
 fi
 done
-if eval \${$as_ac_Search+:} false; then :
+if eval test \${$as_ac_Search+y}
+then :
 
-else
-  eval "$as_ac_Search=no"
+else case e in #(
+  e) eval "$as_ac_Search=no" ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
 eval ac_res=\$$as_ac_Search
-	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
-$as_echo "$ac_res" >&6; }
+	       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+printf "%s\n" "$ac_res" >&6; }
 eval ac_res=\$$as_ac_Search
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   lapack_found=yes
 fi
 
   else
-    as_ac_Search=`$as_echo "ac_cv_search_$search_for" | $as_tr_sh`
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing $search_for" >&5
-$as_echo_n "checking for library containing $search_for... " >&6; }
-if eval \${$as_ac_Search+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    as_ac_Search=`printf "%s\n" "ac_cv_search_$search_for" | sed "$as_sed_sh"`
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing $search_for" >&5
+printf %s "checking for library containing $search_for... " >&6; }
+if eval test \${$as_ac_Search+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char $search_for ();
+namespace conftest {
+  extern "C" int $search_for ();
+}
 int
-main ()
+main (void)
 {
-return $search_for ();
+return conftest::$search_for ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   eval "$as_ac_Search=\$ac_res"
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if eval \${$as_ac_Search+:} false; then :
+  if eval test \${$as_ac_Search+y}
+then :
   break
 fi
 done
-if eval \${$as_ac_Search+:} false; then :
+if eval test \${$as_ac_Search+y}
+then :
 
-else
-  eval "$as_ac_Search=no"
+else case e in #(
+  e) eval "$as_ac_Search=no" ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
 eval ac_res=\$$as_ac_Search
-	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
-$as_echo "$ac_res" >&6; }
+	       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+printf "%s\n" "$ac_res" >&6; }
 eval ac_res=\$$as_ac_Search
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   lapack_found=yes
 fi
@@ -6039,10 +6996,10 @@ fi
 
 # if not found, then use internal lapack with external blas
 if test -z "$lapack_found" ; then
-{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: using internal lapack, could be inefficient" >&5
-$as_echo "$as_me: WARNING: using internal lapack, could be inefficient" >&2;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using internal lapack, could be inefficient" >&5
+printf "%s\n" "$as_me: WARNING: using internal lapack, could be inefficient" >&2;}
 else
-$as_echo "#define __PLUMED_HAS_EXTERNAL_LAPACK 1" >>confdefs.h
+printf "%s\n" "#define __PLUMED_HAS_EXTERNAL_LAPACK 1" >>confdefs.h
 
 fi
 
@@ -6053,7 +7010,7 @@ fi
 # in the latter case, also (internal) lapack names will be underscored consistently
 if test "$blas_found" = nounderscore
 then
-  $as_echo "#define F77_NO_UNDERSCORE 1" >>confdefs.h
+  printf "%s\n" "#define F77_NO_UNDERSCORE 1" >>confdefs.h
 
 fi
 
@@ -6062,14 +7019,15 @@ if test -n "$blas_found" ; then
 
 
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether sdot returns float" >&5
-$as_echo_n "checking whether sdot returns float... " >&6; }
-if test "$cross_compiling" = yes; then :
-   { $as_echo "$as_me:${as_lineno-$LINENO}: result: not checked (cross compiling)" >&5
-$as_echo "not checked (cross compiling)" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether sdot returns float" >&5
+printf %s "checking whether sdot returns float... " >&6; }
+if test "$cross_compiling" = yes
+then :
+   { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: not checked (cross compiling)" >&5
+printf "%s\n" "not checked (cross compiling)" >&6; }
 
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+else case e in #(
+  e) cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 #if ! defined(F77_NO_UNDERSCORE)
@@ -6095,29 +7053,33 @@ int main(){
 }
 
 _ACEOF
-if ac_fn_cxx_try_run "$LINENO"; then :
-   sdot_returns_float=yes ; { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-   sdot_returns_float=no ;  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
+if ac_fn_cxx_try_run "$LINENO"
+then :
+   sdot_returns_float=yes ; { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e)  sdot_returns_float=no ;  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }  ;;
+esac
 fi
 rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
-  conftest.$ac_objext conftest.beam conftest.$ac_ext
+  conftest.$ac_objext conftest.beam conftest.$ac_ext ;;
+esac
 fi
 
 
 if test "$sdot_returns_float" = no ;
 then
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether sdot returns double" >&5
-$as_echo_n "checking whether sdot returns double... " >&6; }
-if test "$cross_compiling" = yes; then :
-   { $as_echo "$as_me:${as_lineno-$LINENO}: result: not checked (cross compiling)" >&5
-$as_echo "not checked (cross compiling)" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether sdot returns double" >&5
+printf %s "checking whether sdot returns double... " >&6; }
+if test "$cross_compiling" = yes
+then :
+   { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: not checked (cross compiling)" >&5
+printf "%s\n" "not checked (cross compiling)" >&6; }
 
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+else case e in #(
+  e) cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 #if ! defined(F77_NO_UNDERSCORE)
@@ -6143,35 +7105,38 @@ int main(){
 }
 
 _ACEOF
-if ac_fn_cxx_try_run "$LINENO"; then :
-   sdot_returns_double=yes ; { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-   sdot_returns_double=no ;  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
+if ac_fn_cxx_try_run "$LINENO"
+then :
+   sdot_returns_double=yes ; { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e)  sdot_returns_double=no ;  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }  ;;
+esac
 fi
 rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
-  conftest.$ac_objext conftest.beam conftest.$ac_ext
+  conftest.$ac_objext conftest.beam conftest.$ac_ext ;;
+esac
 fi
 
 
 fi
 
 if test "$sdot_returns_double" = yes ; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: Setting workaround for blas float functions returning double" >&5
-$as_echo "$as_me: Setting workaround for blas float functions returning double" >&6;}
-  $as_echo "#define __PLUMED_BLAS_RETURNS_FLOAT double" >>confdefs.h
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Setting workaround for blas float functions returning double" >&5
+printf "%s\n" "$as_me: Setting workaround for blas float functions returning double" >&6;}
+  printf "%s\n" "#define __PLUMED_BLAS_RETURNS_FLOAT double" >>confdefs.h
 
   if test -n "$lapack_found" ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: Setting workaround for lapack float functions returning double" >&5
-$as_echo "$as_me: Setting workaround for lapack float functions returning double" >&6;}
-    $as_echo "#define __PLUMED_LAPACK_RETURNS_FLOAT double" >>confdefs.h
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Setting workaround for lapack float functions returning double" >&5
+printf "%s\n" "$as_me: Setting workaround for lapack float functions returning double" >&6;}
+    printf "%s\n" "#define __PLUMED_LAPACK_RETURNS_FLOAT double" >>confdefs.h
 
   fi
 else if test "$sdot_returns_float" = no && test "$sdot_returns_double" = no ;
 then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: There is a problem with your blas implementation" >&5
-$as_echo "$as_me: WARNING: There is a problem with your blas implementation" >&2;}
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: There is a problem with your blas implementation" >&5
+printf "%s\n" "$as_me: WARNING: There is a problem with your blas implementation" >&2;}
 fi
 
 fi
@@ -6181,8 +7146,8 @@ fi
 #### End of compulsory libraries ####
 
 #### Optional libraries ####
-{ $as_echo "$as_me:${as_lineno-$LINENO}: Now we will check for optional headers and libraries" >&5
-$as_echo "$as_me: Now we will check for optional headers and libraries" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: Now we will check for optional headers and libraries" >&5
+printf "%s\n" "$as_me: Now we will check for optional headers and libraries" >&6;}
 
 #############################################################
 # I add the possibility to completely remove molfile_plugins
@@ -6198,520 +7163,165 @@ if test $molfile_plugins = true ; then
 # Check for molfile_plugins and use internal fallback if not found. TG
 
 # We always have molfile, now
-$as_echo "#define __PLUMED_HAS_MOLFILE_PLUGINS 1" >>confdefs.h
+printf "%s\n" "#define __PLUMED_HAS_MOLFILE_PLUGINS 1" >>confdefs.h
 
 
   if test "$external_molfile_plugins" = true ; then
-    ac_ext=cpp
-ac_cpp='$CXXCPP $CPPFLAGS'
-ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking how to run the C++ preprocessor" >&5
-$as_echo_n "checking how to run the C++ preprocessor... " >&6; }
-if test -z "$CXXCPP"; then
-  if ${ac_cv_prog_CXXCPP+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-      # Double quotes because CXXCPP needs to be expanded
-    for CXXCPP in "$CXX -E" "/lib/cpp"
-    do
-      ac_preproc_ok=false
-for ac_cxx_preproc_warn_flag in '' yes
-do
-  # Use a header file that comes with gcc, so configuring glibc
-  # with a fresh cross-compiler works.
-  # Prefer <limits.h> to <assert.h> if __STDC__ is defined, since
-  # <limits.h> exists even on freestanding compilers.
-  # On the NeXT, cc -E runs the code through the compiler's parser,
-  # not just through cpp. "Syntax error" is here to catch this case.
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#ifdef __STDC__
-# include <limits.h>
-#else
-# include <assert.h>
-#endif
-		     Syntax error
-_ACEOF
-if ac_fn_cxx_try_cpp "$LINENO"; then :
-
-else
-  # Broken: fails on valid input.
-continue
-fi
-rm -f conftest.err conftest.i conftest.$ac_ext
-
-  # OK, works on sane cases.  Now check whether nonexistent headers
-  # can be detected and how.
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#include <ac_nonexistent.h>
-_ACEOF
-if ac_fn_cxx_try_cpp "$LINENO"; then :
-  # Broken: success on invalid input.
-continue
-else
-  # Passes both tests.
-ac_preproc_ok=:
-break
-fi
-rm -f conftest.err conftest.i conftest.$ac_ext
-
-done
-# Because of `break', _AC_PREPROC_IFELSE's cleaning code was skipped.
-rm -f conftest.i conftest.err conftest.$ac_ext
-if $ac_preproc_ok; then :
-  break
-fi
-
-    done
-    ac_cv_prog_CXXCPP=$CXXCPP
-
-fi
-  CXXCPP=$ac_cv_prog_CXXCPP
-else
-  ac_cv_prog_CXXCPP=$CXXCPP
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $CXXCPP" >&5
-$as_echo "$CXXCPP" >&6; }
-ac_preproc_ok=false
-for ac_cxx_preproc_warn_flag in '' yes
-do
-  # Use a header file that comes with gcc, so configuring glibc
-  # with a fresh cross-compiler works.
-  # Prefer <limits.h> to <assert.h> if __STDC__ is defined, since
-  # <limits.h> exists even on freestanding compilers.
-  # On the NeXT, cc -E runs the code through the compiler's parser,
-  # not just through cpp. "Syntax error" is here to catch this case.
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#ifdef __STDC__
-# include <limits.h>
-#else
-# include <assert.h>
-#endif
-		     Syntax error
-_ACEOF
-if ac_fn_cxx_try_cpp "$LINENO"; then :
-
-else
-  # Broken: fails on valid input.
-continue
-fi
-rm -f conftest.err conftest.i conftest.$ac_ext
-
-  # OK, works on sane cases.  Now check whether nonexistent headers
-  # can be detected and how.
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#include <ac_nonexistent.h>
-_ACEOF
-if ac_fn_cxx_try_cpp "$LINENO"; then :
-  # Broken: success on invalid input.
-continue
-else
-  # Passes both tests.
-ac_preproc_ok=:
-break
-fi
-rm -f conftest.err conftest.i conftest.$ac_ext
-
-done
-# Because of `break', _AC_PREPROC_IFELSE's cleaning code was skipped.
-rm -f conftest.i conftest.err conftest.$ac_ext
-if $ac_preproc_ok; then :
-
-else
-  { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
-$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
-as_fn_error $? "C++ preprocessor \"$CXXCPP\" fails sanity check
-See \`config.log' for more details" "$LINENO" 5; }
-fi
-
-ac_ext=cpp
-ac_cpp='$CXXCPP $CPPFLAGS'
-ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
-
-
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for grep that handles long lines and -e" >&5
-$as_echo_n "checking for grep that handles long lines and -e... " >&6; }
-if ${ac_cv_path_GREP+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  if test -z "$GREP"; then
-  ac_path_GREP_found=false
-  # Loop through the user's path and test for each of PROGNAME-LIST
-  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in $PATH$PATH_SEPARATOR/usr/xpg4/bin
-do
-  IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
-    for ac_prog in grep ggrep; do
-    for ac_exec_ext in '' $ac_executable_extensions; do
-      ac_path_GREP="$as_dir/$ac_prog$ac_exec_ext"
-      as_fn_executable_p "$ac_path_GREP" || continue
-# Check for GNU ac_path_GREP and select it if it is found.
-  # Check for GNU $ac_path_GREP
-case `"$ac_path_GREP" --version 2>&1` in
-*GNU*)
-  ac_cv_path_GREP="$ac_path_GREP" ac_path_GREP_found=:;;
-*)
-  ac_count=0
-  $as_echo_n 0123456789 >"conftest.in"
-  while :
-  do
-    cat "conftest.in" "conftest.in" >"conftest.tmp"
-    mv "conftest.tmp" "conftest.in"
-    cp "conftest.in" "conftest.nl"
-    $as_echo 'GREP' >> "conftest.nl"
-    "$ac_path_GREP" -e 'GREP$' -e '-(cannot match)-' < "conftest.nl" >"conftest.out" 2>/dev/null || break
-    diff "conftest.out" "conftest.nl" >/dev/null 2>&1 || break
-    as_fn_arith $ac_count + 1 && ac_count=$as_val
-    if test $ac_count -gt ${ac_path_GREP_max-0}; then
-      # Best one so far, save it but keep looking for a better one
-      ac_cv_path_GREP="$ac_path_GREP"
-      ac_path_GREP_max=$ac_count
-    fi
-    # 10*(2^10) chars as input seems more than enough
-    test $ac_count -gt 10 && break
-  done
-  rm -f conftest.in conftest.tmp conftest.nl conftest.out;;
-esac
-
-      $ac_path_GREP_found && break 3
-    done
-  done
-  done
-IFS=$as_save_IFS
-  if test -z "$ac_cv_path_GREP"; then
-    as_fn_error $? "no acceptable grep could be found in $PATH$PATH_SEPARATOR/usr/xpg4/bin" "$LINENO" 5
-  fi
-else
-  ac_cv_path_GREP=$GREP
-fi
-
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_path_GREP" >&5
-$as_echo "$ac_cv_path_GREP" >&6; }
- GREP="$ac_cv_path_GREP"
-
-
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for egrep" >&5
-$as_echo_n "checking for egrep... " >&6; }
-if ${ac_cv_path_EGREP+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  if echo a | $GREP -E '(a|b)' >/dev/null 2>&1
-   then ac_cv_path_EGREP="$GREP -E"
-   else
-     if test -z "$EGREP"; then
-  ac_path_EGREP_found=false
-  # Loop through the user's path and test for each of PROGNAME-LIST
-  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in $PATH$PATH_SEPARATOR/usr/xpg4/bin
+    ac_header= ac_cache=
+for ac_item in $ac_header_cxx_list
 do
-  IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
-    for ac_prog in egrep; do
-    for ac_exec_ext in '' $ac_executable_extensions; do
-      ac_path_EGREP="$as_dir/$ac_prog$ac_exec_ext"
-      as_fn_executable_p "$ac_path_EGREP" || continue
-# Check for GNU ac_path_EGREP and select it if it is found.
-  # Check for GNU $ac_path_EGREP
-case `"$ac_path_EGREP" --version 2>&1` in
-*GNU*)
-  ac_cv_path_EGREP="$ac_path_EGREP" ac_path_EGREP_found=:;;
-*)
-  ac_count=0
-  $as_echo_n 0123456789 >"conftest.in"
-  while :
-  do
-    cat "conftest.in" "conftest.in" >"conftest.tmp"
-    mv "conftest.tmp" "conftest.in"
-    cp "conftest.in" "conftest.nl"
-    $as_echo 'EGREP' >> "conftest.nl"
-    "$ac_path_EGREP" 'EGREP$' < "conftest.nl" >"conftest.out" 2>/dev/null || break
-    diff "conftest.out" "conftest.nl" >/dev/null 2>&1 || break
-    as_fn_arith $ac_count + 1 && ac_count=$as_val
-    if test $ac_count -gt ${ac_path_EGREP_max-0}; then
-      # Best one so far, save it but keep looking for a better one
-      ac_cv_path_EGREP="$ac_path_EGREP"
-      ac_path_EGREP_max=$ac_count
+  if test $ac_cache; then
+    ac_fn_cxx_check_header_compile "$LINENO" $ac_header ac_cv_header_$ac_cache "$ac_includes_default"
+    if eval test \"x\$ac_cv_header_$ac_cache\" = xyes; then
+      printf "%s\n" "#define $ac_item 1" >> confdefs.h
     fi
-    # 10*(2^10) chars as input seems more than enough
-    test $ac_count -gt 10 && break
-  done
-  rm -f conftest.in conftest.tmp conftest.nl conftest.out;;
-esac
-
-      $ac_path_EGREP_found && break 3
-    done
-  done
-  done
-IFS=$as_save_IFS
-  if test -z "$ac_cv_path_EGREP"; then
-    as_fn_error $? "no acceptable egrep could be found in $PATH$PATH_SEPARATOR/usr/xpg4/bin" "$LINENO" 5
+    ac_header= ac_cache=
+  elif test $ac_header; then
+    ac_cache=$ac_item
+  else
+    ac_header=$ac_item
   fi
-else
-  ac_cv_path_EGREP=$EGREP
-fi
-
-   fi
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_path_EGREP" >&5
-$as_echo "$ac_cv_path_EGREP" >&6; }
- EGREP="$ac_cv_path_EGREP"
-
-
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for ANSI C header files" >&5
-$as_echo_n "checking for ANSI C header files... " >&6; }
-if ${ac_cv_header_stdc+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#include <stdlib.h>
-#include <stdarg.h>
-#include <string.h>
-#include <float.h>
-
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
-  ac_cv_header_stdc=yes
-else
-  ac_cv_header_stdc=no
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-
-if test $ac_cv_header_stdc = yes; then
-  # SunOS 4.x string.h does not declare mem*, contrary to ANSI.
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#include <string.h>
-
-_ACEOF
-if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
-  $EGREP "memchr" >/dev/null 2>&1; then :
-
-else
-  ac_cv_header_stdc=no
-fi
-rm -f conftest*
-
-fi
-
-if test $ac_cv_header_stdc = yes; then
-  # ISC 2.0.2 stdlib.h does not declare free, contrary to ANSI.
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#include <stdlib.h>
-
-_ACEOF
-if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
-  $EGREP "free" >/dev/null 2>&1; then :
+done
 
-else
-  ac_cv_header_stdc=no
-fi
-rm -f conftest*
 
-fi
 
-if test $ac_cv_header_stdc = yes; then
-  # /bin/cc in Irix-4.0.5 gets non-ANSI ctype macros unless using -ansi.
-  if test "$cross_compiling" = yes; then :
-  :
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#include <ctype.h>
-#include <stdlib.h>
-#if ((' ' & 0x0FF) == 0x020)
-# define ISLOWER(c) ('a' <= (c) && (c) <= 'z')
-# define TOUPPER(c) (ISLOWER(c) ? 'A' + ((c) - 'a') : (c))
-#else
-# define ISLOWER(c) \
-		   (('a' <= (c) && (c) <= 'i') \
-		     || ('j' <= (c) && (c) <= 'r') \
-		     || ('s' <= (c) && (c) <= 'z'))
-# define TOUPPER(c) (ISLOWER(c) ? ((c) | 0x40) : (c))
-#endif
 
-#define XOR(e, f) (((e) && !(f)) || (!(e) && (f)))
-int
-main ()
-{
-  int i;
-  for (i = 0; i < 256; i++)
-    if (XOR (islower (i), ISLOWER (i))
-	|| toupper (i) != TOUPPER (i))
-      return 2;
-  return 0;
-}
-_ACEOF
-if ac_fn_cxx_try_run "$LINENO"; then :
 
-else
-  ac_cv_header_stdc=no
-fi
-rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
-  conftest.$ac_objext conftest.beam conftest.$ac_ext
-fi
 
-fi
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_header_stdc" >&5
-$as_echo "$ac_cv_header_stdc" >&6; }
-if test $ac_cv_header_stdc = yes; then
 
-$as_echo "#define STDC_HEADERS 1" >>confdefs.h
 
-fi
+if test $ac_cv_header_stdlib_h = yes && test $ac_cv_header_string_h = yes
+then :
 
-# On IRIX 5.3, sys/types and inttypes.h are conflicting.
-for ac_header in sys/types.h sys/stat.h stdlib.h string.h memory.h strings.h \
-		  inttypes.h stdint.h unistd.h
-do :
-  as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
-ac_fn_cxx_check_header_compile "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default
-"
-if eval test \"x\$"$as_ac_Header"\" = x"yes"; then :
-  cat >>confdefs.h <<_ACEOF
-#define `$as_echo "HAVE_$ac_header" | $as_tr_cpp` 1
-_ACEOF
+printf "%s\n" "#define STDC_HEADERS 1" >>confdefs.h
 
 fi
 
-done
-
-
-
     found=ko
     __PLUMED_HAS_EXTERNAL_MOLFILE_PLUGINS=no
-    ac_fn_cxx_check_header_mongrel "$LINENO" "libmolfile_plugin.h" "ac_cv_header_libmolfile_plugin_h" "$ac_includes_default"
-if test "x$ac_cv_header_libmolfile_plugin_h" = xyes; then :
+    ac_fn_cxx_check_header_compile "$LINENO" "libmolfile_plugin.h" "ac_cv_header_libmolfile_plugin_h" "$ac_includes_default"
+if test "x$ac_cv_header_libmolfile_plugin_h" = xyes
+then :
 
 
   if test "${libsearch}" = true ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing molfile_dcdplugin_init" >&5
-$as_echo_n "checking for library containing molfile_dcdplugin_init... " >&6; }
-if ${ac_cv_search_molfile_dcdplugin_init+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing molfile_dcdplugin_init" >&5
+printf %s "checking for library containing molfile_dcdplugin_init... " >&6; }
+if test ${ac_cv_search_molfile_dcdplugin_init+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char molfile_dcdplugin_init ();
+namespace conftest {
+  extern "C" int molfile_dcdplugin_init ();
+}
 int
-main ()
+main (void)
 {
-return molfile_dcdplugin_init ();
+return conftest::molfile_dcdplugin_init ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' molfile_plugin; do
+for ac_lib in '' molfile_plugin
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_molfile_dcdplugin_init=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_molfile_dcdplugin_init+:} false; then :
+  if test ${ac_cv_search_molfile_dcdplugin_init+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_molfile_dcdplugin_init+:} false; then :
+if test ${ac_cv_search_molfile_dcdplugin_init+y}
+then :
 
-else
-  ac_cv_search_molfile_dcdplugin_init=no
+else case e in #(
+  e) ac_cv_search_molfile_dcdplugin_init=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_molfile_dcdplugin_init" >&5
-$as_echo "$ac_cv_search_molfile_dcdplugin_init" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_molfile_dcdplugin_init" >&5
+printf "%s\n" "$ac_cv_search_molfile_dcdplugin_init" >&6; }
 ac_res=$ac_cv_search_molfile_dcdplugin_init
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
 
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing molfile_dcdplugin_init" >&5
-$as_echo_n "checking for library containing molfile_dcdplugin_init... " >&6; }
-if ${ac_cv_search_molfile_dcdplugin_init+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing molfile_dcdplugin_init" >&5
+printf %s "checking for library containing molfile_dcdplugin_init... " >&6; }
+if test ${ac_cv_search_molfile_dcdplugin_init+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char molfile_dcdplugin_init ();
+namespace conftest {
+  extern "C" int molfile_dcdplugin_init ();
+}
 int
-main ()
+main (void)
 {
-return molfile_dcdplugin_init ();
+return conftest::molfile_dcdplugin_init ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_molfile_dcdplugin_init=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_molfile_dcdplugin_init+:} false; then :
+  if test ${ac_cv_search_molfile_dcdplugin_init+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_molfile_dcdplugin_init+:} false; then :
+if test ${ac_cv_search_molfile_dcdplugin_init+y}
+then :
 
-else
-  ac_cv_search_molfile_dcdplugin_init=no
+else case e in #(
+  e) ac_cv_search_molfile_dcdplugin_init=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_molfile_dcdplugin_init" >&5
-$as_echo "$ac_cv_search_molfile_dcdplugin_init" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_molfile_dcdplugin_init" >&5
+printf "%s\n" "$ac_cv_search_molfile_dcdplugin_init" >&6; }
 ac_res=$ac_cv_search_molfile_dcdplugin_init
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
@@ -6721,21 +7331,20 @@ fi
 
 fi
 
-
     if test $found = ok ; then
-       $as_echo "#define __PLUMED_HAS_EXTERNAL_MOLFILE_PLUGINS 1" >>confdefs.h
+       printf "%s\n" "#define __PLUMED_HAS_EXTERNAL_MOLFILE_PLUGINS 1" >>confdefs.h
 
        __PLUMED_HAS_EXTERNAL_MOLFILE_PLUGINS=yes
     else
-       { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_EXTERNAL_MOLFILE_PLUGINS" >&5
-$as_echo "$as_me: WARNING: cannot enable __PLUMED_HAS_EXTERNAL_MOLFILE_PLUGINS" >&2;}
+       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_EXTERNAL_MOLFILE_PLUGINS" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable __PLUMED_HAS_EXTERNAL_MOLFILE_PLUGINS" >&2;}
     fi
 
     if test "$__PLUMED_HAS_EXTERNAL_MOLFILE_PLUGINS" != yes ; then
-      { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: using internal molfile_plugins, which only support dcd/xtc/trr/trj/crd files" >&5
-$as_echo "$as_me: WARNING: using internal molfile_plugins, which only support dcd/xtc/trr/trj/crd files" >&2;}
+      { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using internal molfile_plugins, which only support dcd/xtc/trr/trj/crd files" >&5
+printf "%s\n" "$as_me: WARNING: using internal molfile_plugins, which only support dcd/xtc/trr/trj/crd files" >&2;}
     else
-      $as_echo "#define __PLUMED_HAS_EXTERNAL_MOLFILE_PLUGINS 1" >>confdefs.h
+      printf "%s\n" "#define __PLUMED_HAS_EXTERNAL_MOLFILE_PLUGINS 1" >>confdefs.h
 
     fi
   fi
@@ -6744,43 +7353,44 @@ fi
 # this is special and is also attached to STATIC_LIBS
 # this flag should be used also when linking MD engines to allow plumed
 # to be loaded later
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for dlopen in -ldl" >&5
-$as_echo_n "checking for dlopen in -ldl... " >&6; }
-if ${ac_cv_lib_dl_dlopen+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_check_lib_save_LIBS=$LIBS
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for dlopen in -ldl" >&5
+printf %s "checking for dlopen in -ldl... " >&6; }
+if test ${ac_cv_lib_dl_dlopen+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_check_lib_save_LIBS=$LIBS
 LIBS="-ldl  $LIBS"
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char dlopen ();
+namespace conftest {
+  extern "C" int dlopen ();
+}
 int
-main ()
+main (void)
 {
-return dlopen ();
+return conftest::dlopen ();
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_lib_dl_dlopen=yes
-else
-  ac_cv_lib_dl_dlopen=no
+else case e in #(
+  e) ac_cv_lib_dl_dlopen=no ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
-LIBS=$ac_check_lib_save_LIBS
+LIBS=$ac_check_lib_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_dl_dlopen" >&5
-$as_echo "$ac_cv_lib_dl_dlopen" >&6; }
-if test "x$ac_cv_lib_dl_dlopen" = xyes; then :
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_dl_dlopen" >&5
+printf "%s\n" "$ac_cv_lib_dl_dlopen" >&6; }
+if test "x$ac_cv_lib_dl_dlopen" = xyes
+then :
   STATIC_LIBS="-ldl $STATIC_LIBS" LIBS="-ldl $LIBS"
 fi
 
@@ -6789,120 +7399,129 @@ fi
 
     found=ko
     __PLUMED_HAS_DLADDR=no
-    ac_fn_cxx_check_header_mongrel "$LINENO" "dlfcn.h" "ac_cv_header_dlfcn_h" "$ac_includes_default"
-if test "x$ac_cv_header_dlfcn_h" = xyes; then :
+    ac_fn_cxx_check_header_compile "$LINENO" "dlfcn.h" "ac_cv_header_dlfcn_h" "$ac_includes_default"
+if test "x$ac_cv_header_dlfcn_h" = xyes
+then :
 
 
   if test "${libsearch}" = true ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing dladdr" >&5
-$as_echo_n "checking for library containing dladdr... " >&6; }
-if ${ac_cv_search_dladdr+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing dladdr" >&5
+printf %s "checking for library containing dladdr... " >&6; }
+if test ${ac_cv_search_dladdr+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char dladdr ();
+namespace conftest {
+  extern "C" int dladdr ();
+}
 int
-main ()
+main (void)
 {
-return dladdr ();
+return conftest::dladdr ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_dladdr=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_dladdr+:} false; then :
+  if test ${ac_cv_search_dladdr+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_dladdr+:} false; then :
+if test ${ac_cv_search_dladdr+y}
+then :
 
-else
-  ac_cv_search_dladdr=no
+else case e in #(
+  e) ac_cv_search_dladdr=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dladdr" >&5
-$as_echo "$ac_cv_search_dladdr" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dladdr" >&5
+printf "%s\n" "$ac_cv_search_dladdr" >&6; }
 ac_res=$ac_cv_search_dladdr
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
 
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing dladdr" >&5
-$as_echo_n "checking for library containing dladdr... " >&6; }
-if ${ac_cv_search_dladdr+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing dladdr" >&5
+printf %s "checking for library containing dladdr... " >&6; }
+if test ${ac_cv_search_dladdr+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char dladdr ();
+namespace conftest {
+  extern "C" int dladdr ();
+}
 int
-main ()
+main (void)
 {
-return dladdr ();
+return conftest::dladdr ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_dladdr=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_dladdr+:} false; then :
+  if test ${ac_cv_search_dladdr+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_dladdr+:} false; then :
+if test ${ac_cv_search_dladdr+y}
+then :
 
-else
-  ac_cv_search_dladdr=no
+else case e in #(
+  e) ac_cv_search_dladdr=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dladdr" >&5
-$as_echo "$ac_cv_search_dladdr" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dladdr" >&5
+printf "%s\n" "$ac_cv_search_dladdr" >&6; }
 ac_res=$ac_cv_search_dladdr
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
@@ -6912,14 +7531,13 @@ fi
 
 fi
 
-
     if test $found = ok ; then
-       $as_echo "#define __PLUMED_HAS_DLADDR 1" >>confdefs.h
+       printf "%s\n" "#define __PLUMED_HAS_DLADDR 1" >>confdefs.h
 
        __PLUMED_HAS_DLADDR=yes
     else
-       { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_DLADDR" >&5
-$as_echo "$as_me: WARNING: cannot enable __PLUMED_HAS_DLADDR" >&2;}
+       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_DLADDR" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable __PLUMED_HAS_DLADDR" >&2;}
     fi
 
 
@@ -6929,120 +7547,129 @@ if test $mpi = true ; then
 
     found=ko
     __PLUMED_HAS_MPI=no
-    ac_fn_cxx_check_header_mongrel "$LINENO" "mpi.h" "ac_cv_header_mpi_h" "$ac_includes_default"
-if test "x$ac_cv_header_mpi_h" = xyes; then :
+    ac_fn_cxx_check_header_compile "$LINENO" "mpi.h" "ac_cv_header_mpi_h" "$ac_includes_default"
+if test "x$ac_cv_header_mpi_h" = xyes
+then :
 
 
   if test "${libsearch}" = true ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing MPI_Init" >&5
-$as_echo_n "checking for library containing MPI_Init... " >&6; }
-if ${ac_cv_search_MPI_Init+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing MPI_Init" >&5
+printf %s "checking for library containing MPI_Init... " >&6; }
+if test ${ac_cv_search_MPI_Init+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char MPI_Init ();
+namespace conftest {
+  extern "C" int MPI_Init ();
+}
 int
-main ()
+main (void)
 {
-return MPI_Init ();
+return conftest::MPI_Init ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_MPI_Init=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_MPI_Init+:} false; then :
+  if test ${ac_cv_search_MPI_Init+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_MPI_Init+:} false; then :
+if test ${ac_cv_search_MPI_Init+y}
+then :
 
-else
-  ac_cv_search_MPI_Init=no
+else case e in #(
+  e) ac_cv_search_MPI_Init=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_MPI_Init" >&5
-$as_echo "$ac_cv_search_MPI_Init" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_MPI_Init" >&5
+printf "%s\n" "$ac_cv_search_MPI_Init" >&6; }
 ac_res=$ac_cv_search_MPI_Init
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
 
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing MPI_Init" >&5
-$as_echo_n "checking for library containing MPI_Init... " >&6; }
-if ${ac_cv_search_MPI_Init+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing MPI_Init" >&5
+printf %s "checking for library containing MPI_Init... " >&6; }
+if test ${ac_cv_search_MPI_Init+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char MPI_Init ();
+namespace conftest {
+  extern "C" int MPI_Init ();
+}
 int
-main ()
+main (void)
 {
-return MPI_Init ();
+return conftest::MPI_Init ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_MPI_Init=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_MPI_Init+:} false; then :
+  if test ${ac_cv_search_MPI_Init+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_MPI_Init+:} false; then :
+if test ${ac_cv_search_MPI_Init+y}
+then :
 
-else
-  ac_cv_search_MPI_Init=no
+else case e in #(
+  e) ac_cv_search_MPI_Init=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_MPI_Init" >&5
-$as_echo "$ac_cv_search_MPI_Init" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_MPI_Init" >&5
+printf "%s\n" "$ac_cv_search_MPI_Init" >&6; }
 ac_res=$ac_cv_search_MPI_Init
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
@@ -7052,14 +7679,13 @@ fi
 
 fi
 
-
     if test $found = ok ; then
-       $as_echo "#define __PLUMED_HAS_MPI 1" >>confdefs.h
+       printf "%s\n" "#define __PLUMED_HAS_MPI 1" >>confdefs.h
 
        __PLUMED_HAS_MPI=yes
     else
-       { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_MPI" >&5
-$as_echo "$as_me: WARNING: cannot enable __PLUMED_HAS_MPI" >&2;}
+       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_MPI" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable __PLUMED_HAS_MPI" >&2;}
     fi
 
   if test "$__PLUMED_HAS_MPI" = yes; then
@@ -7071,76 +7697,89 @@ fi
 
 # search for openmp is automatically disabled by autoconf
 # when configuring with --disable-openmp
-
-  OPENMP_CXXFLAGS=
-  # Check whether --enable-openmp was given.
-if test "${enable_openmp+set}" = set; then :
+if test -e penmp || test -e mp; then
+  as_fn_error $? "AC_OPENMP clobbers files named 'mp' and 'penmp'. Aborting configure because one of these files already exists." "$LINENO" 5
+fi
+# Check whether --enable-openmp was given.
+if test ${enable_openmp+y}
+then :
   enableval=$enable_openmp;
 fi
 
+  OPENMP_CXXFLAGS=
   if test "$enable_openmp" != no; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for $CXX option to support OpenMP" >&5
-$as_echo_n "checking for $CXX option to support OpenMP... " >&6; }
-if ${ac_cv_prog_cxx_openmp+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $CXX option to support OpenMP" >&5
+printf %s "checking for $CXX option to support OpenMP... " >&6; }
+if test ${ac_cv_prog_cxx_openmp+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_cv_prog_cxx_openmp='not found'
+                                                                        for ac_option in '' -fopenmp -xopenmp -openmp -mp -omp -qsmp=omp -homp \
+                       -Popenmp --openmp; do
+
+        ac_save_CXXFLAGS=$CXXFLAGS
+        CXXFLAGS="$CXXFLAGS $ac_option"
+        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 #ifndef _OPENMP
- choke me
+#error "OpenMP not supported"
 #endif
 #include <omp.h>
-int main () { return omp_get_num_threads (); }
+int main (void) { return omp_get_num_threads (); }
 
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
-  ac_cv_prog_cxx_openmp='none needed'
-else
-  ac_cv_prog_cxx_openmp='unsupported'
-	  	  	  	  	  	  	                                	  	  	  	  	  	  for ac_option in -fopenmp -xopenmp -openmp -mp -omp -qsmp=omp -homp \
-                           -Popenmp --openmp; do
-	    ac_save_CXXFLAGS=$CXXFLAGS
-	    CXXFLAGS="$CXXFLAGS $ac_option"
-	    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+if ac_fn_cxx_try_compile "$LINENO"
+then :
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 #ifndef _OPENMP
- choke me
+#error "OpenMP not supported"
 #endif
 #include <omp.h>
-int main () { return omp_get_num_threads (); }
+int main (void) { return omp_get_num_threads (); }
 
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_prog_cxx_openmp=$ac_option
+else case e in #(
+  e) ac_cv_prog_cxx_openmp='unsupported' ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
-	    CXXFLAGS=$ac_save_CXXFLAGS
-	    if test "$ac_cv_prog_cxx_openmp" != unsupported; then
-	      break
-	    fi
-	  done
 fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
+        CXXFLAGS=$ac_save_CXXFLAGS
+
+        if test "$ac_cv_prog_cxx_openmp" != 'not found'; then
+          break
+        fi
+      done
+      if test "$ac_cv_prog_cxx_openmp" = 'not found'; then
+        ac_cv_prog_cxx_openmp='unsupported'
+      elif test "$ac_cv_prog_cxx_openmp" = ''; then
+        ac_cv_prog_cxx_openmp='none needed'
+      fi
+                        rm -f penmp mp ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_prog_cxx_openmp" >&5
-$as_echo "$ac_cv_prog_cxx_openmp" >&6; }
-    case $ac_cv_prog_cxx_openmp in #(
-      "none needed" | unsupported)
-	;; #(
-      *)
-	OPENMP_CXXFLAGS=$ac_cv_prog_cxx_openmp ;;
-    esac
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_prog_cxx_openmp" >&5
+printf "%s\n" "$ac_cv_prog_cxx_openmp" >&6; }
+    if test "$ac_cv_prog_cxx_openmp" != 'unsupported' && \
+       test "$ac_cv_prog_cxx_openmp" != 'none needed'; then
+      OPENMP_CXXFLAGS="$ac_cv_prog_cxx_openmp"
+    fi
   fi
 
 
 
 if test $asmjit = true ; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether architecture is X86/X64" >&5
-$as_echo_n "checking whether architecture is X86/X64... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether architecture is X86/X64" >&5
+printf %s "checking whether architecture is X86/X64... " >&6; }
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
@@ -7153,28 +7792,30 @@ this_is_not_x86_x64
 #endif
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; };
+if ac_fn_cxx_try_compile "$LINENO"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; };
   x86_x64=true
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; } ;
-  x86_x64=false
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; } ;
+  x86_x64=false ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
 fi
 
 if test $asmjit = true && test $x86_x64 = false ; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: asmjit does not support this architecture, it will be disabled" >&5
-$as_echo "$as_me: WARNING: asmjit does not support this architecture, it will be disabled" >&2;}
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: asmjit does not support this architecture, it will be disabled" >&5
+printf "%s\n" "$as_me: WARNING: asmjit does not support this architecture, it will be disabled" >&2;}
   asmjit=false
 fi
 
@@ -7184,115 +7825,123 @@ if test $asmjit = true ; then
   if test `(uname)` = Linux ; then
 
   if test "${libsearch}" = true ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing clock_gettime" >&5
-$as_echo_n "checking for library containing clock_gettime... " >&6; }
-if ${ac_cv_search_clock_gettime+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing clock_gettime" >&5
+printf %s "checking for library containing clock_gettime... " >&6; }
+if test ${ac_cv_search_clock_gettime+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char clock_gettime ();
+namespace conftest {
+  extern "C" int clock_gettime ();
+}
 int
-main ()
+main (void)
 {
-return clock_gettime ();
+return conftest::clock_gettime ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' rt; do
+for ac_lib in '' rt
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_clock_gettime=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_clock_gettime+:} false; then :
+  if test ${ac_cv_search_clock_gettime+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_clock_gettime+:} false; then :
+if test ${ac_cv_search_clock_gettime+y}
+then :
 
-else
-  ac_cv_search_clock_gettime=no
+else case e in #(
+  e) ac_cv_search_clock_gettime=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_clock_gettime" >&5
-$as_echo "$ac_cv_search_clock_gettime" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_clock_gettime" >&5
+printf "%s\n" "$ac_cv_search_clock_gettime" >&6; }
 ac_res=$ac_cv_search_clock_gettime
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
 
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing clock_gettime" >&5
-$as_echo_n "checking for library containing clock_gettime... " >&6; }
-if ${ac_cv_search_clock_gettime+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing clock_gettime" >&5
+printf %s "checking for library containing clock_gettime... " >&6; }
+if test ${ac_cv_search_clock_gettime+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char clock_gettime ();
+namespace conftest {
+  extern "C" int clock_gettime ();
+}
 int
-main ()
+main (void)
 {
-return clock_gettime ();
+return conftest::clock_gettime ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_clock_gettime=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_clock_gettime+:} false; then :
+  if test ${ac_cv_search_clock_gettime+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_clock_gettime+:} false; then :
+if test ${ac_cv_search_clock_gettime+y}
+then :
 
-else
-  ac_cv_search_clock_gettime=no
+else case e in #(
+  e) ac_cv_search_clock_gettime=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_clock_gettime" >&5
-$as_echo "$ac_cv_search_clock_gettime" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_clock_gettime" >&5
+printf "%s\n" "$ac_cv_search_clock_gettime" >&6; }
 ac_res=$ac_cv_search_clock_gettime
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
@@ -7303,13 +7952,13 @@ fi
     found=ok
   fi
   if test "$found" = ok ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: Enabling embedded asmjit" >&5
-$as_echo "$as_me: Enabling embedded asmjit" >&6;}
-    $as_echo "#define __PLUMED_HAS_ASMJIT 1" >>confdefs.h
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Enabling embedded asmjit" >&5
+printf "%s\n" "$as_me: Enabling embedded asmjit" >&6;}
+    printf "%s\n" "#define __PLUMED_HAS_ASMJIT 1" >>confdefs.h
 
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot link clock_gettime on this Linux, asmjit will not be enabled" >&5
-$as_echo "$as_me: WARNING: cannot link clock_gettime on this Linux, asmjit will not be enabled" >&2;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot link clock_gettime on this Linux, asmjit will not be enabled" >&5
+printf "%s\n" "$as_me: WARNING: cannot link clock_gettime on this Linux, asmjit will not be enabled" >&2;}
   fi
 fi
 
@@ -7317,120 +7966,129 @@ if test $dlopen = true ; then
 
     found=ko
     __PLUMED_HAS_DLOPEN=no
-    ac_fn_cxx_check_header_mongrel "$LINENO" "dlfcn.h" "ac_cv_header_dlfcn_h" "$ac_includes_default"
-if test "x$ac_cv_header_dlfcn_h" = xyes; then :
+    ac_fn_cxx_check_header_compile "$LINENO" "dlfcn.h" "ac_cv_header_dlfcn_h" "$ac_includes_default"
+if test "x$ac_cv_header_dlfcn_h" = xyes
+then :
 
 
   if test "${libsearch}" = true ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing dlopen" >&5
-$as_echo_n "checking for library containing dlopen... " >&6; }
-if ${ac_cv_search_dlopen+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing dlopen" >&5
+printf %s "checking for library containing dlopen... " >&6; }
+if test ${ac_cv_search_dlopen+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char dlopen ();
+namespace conftest {
+  extern "C" int dlopen ();
+}
 int
-main ()
+main (void)
 {
-return dlopen ();
+return conftest::dlopen ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_dlopen=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_dlopen+:} false; then :
+  if test ${ac_cv_search_dlopen+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_dlopen+:} false; then :
+if test ${ac_cv_search_dlopen+y}
+then :
 
-else
-  ac_cv_search_dlopen=no
+else case e in #(
+  e) ac_cv_search_dlopen=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dlopen" >&5
-$as_echo "$ac_cv_search_dlopen" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dlopen" >&5
+printf "%s\n" "$ac_cv_search_dlopen" >&6; }
 ac_res=$ac_cv_search_dlopen
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
 
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing dlopen" >&5
-$as_echo_n "checking for library containing dlopen... " >&6; }
-if ${ac_cv_search_dlopen+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing dlopen" >&5
+printf %s "checking for library containing dlopen... " >&6; }
+if test ${ac_cv_search_dlopen+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char dlopen ();
+namespace conftest {
+  extern "C" int dlopen ();
+}
 int
-main ()
+main (void)
 {
-return dlopen ();
+return conftest::dlopen ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_dlopen=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_dlopen+:} false; then :
+  if test ${ac_cv_search_dlopen+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_dlopen+:} false; then :
+if test ${ac_cv_search_dlopen+y}
+then :
 
-else
-  ac_cv_search_dlopen=no
+else case e in #(
+  e) ac_cv_search_dlopen=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dlopen" >&5
-$as_echo "$ac_cv_search_dlopen" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dlopen" >&5
+printf "%s\n" "$ac_cv_search_dlopen" >&6; }
 ac_res=$ac_cv_search_dlopen
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
@@ -7440,14 +8098,13 @@ fi
 
 fi
 
-
     if test $found = ok ; then
-       $as_echo "#define __PLUMED_HAS_DLOPEN 1" >>confdefs.h
+       printf "%s\n" "#define __PLUMED_HAS_DLOPEN 1" >>confdefs.h
 
        __PLUMED_HAS_DLOPEN=yes
     else
-       { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_DLOPEN" >&5
-$as_echo "$as_me: WARNING: cannot enable __PLUMED_HAS_DLOPEN" >&2;}
+       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_DLOPEN" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable __PLUMED_HAS_DLOPEN" >&2;}
     fi
 
 fi
@@ -7476,8 +8133,8 @@ if test $rtld_default = true ; then
     fi
 
     # check without libraries
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking RTLD_DEFAULT without extra libs" >&5
-$as_echo_n "checking RTLD_DEFAULT without extra libs... " >&6; }
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking RTLD_DEFAULT without extra libs" >&5
+printf %s "checking RTLD_DEFAULT without extra libs... " >&6; }
     cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
@@ -7490,22 +8147,24 @@ main ()
 }
 
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"
+then :
   found=ok
-          { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-
+          { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+       ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
     if test "$found" = "ko" ; then
       if test "$multiple" = "yes" ; then
-        { $as_echo "$as_me:${as_lineno-$LINENO}: checking RTLD_DEFAULT with $all_LIBS" >&5
-$as_echo_n "checking RTLD_DEFAULT with $all_LIBS... " >&6; }
+        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking RTLD_DEFAULT with $all_LIBS" >&5
+printf %s "checking RTLD_DEFAULT with $all_LIBS... " >&6; }
         LIBS="$all_LIBS $LIBS"
         cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
@@ -7519,22 +8178,24 @@ main ()
 }
 
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"
+then :
   found=ok
-              { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-
+              { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+           ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
       else
         for testlib in $testlibs
         do
-          { $as_echo "$as_me:${as_lineno-$LINENO}: checking RTLD_DEFAULT with -l$testlib" >&5
-$as_echo_n "checking RTLD_DEFAULT with -l$testlib... " >&6; }
+          { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking RTLD_DEFAULT with -l$testlib" >&5
+printf %s "checking RTLD_DEFAULT with -l$testlib... " >&6; }
           LIBS="-l$testlib $LIBS"
           cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
@@ -7548,16 +8209,18 @@ main ()
 }
 
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"
+then :
   found=ok
-                { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-
+                { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+           ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
           if test $found = ok ; then
             break
@@ -7568,12 +8231,12 @@ rm -f core conftest.err conftest.$ac_objext \
     fi
 
     if test $found = ok ; then
-      $as_echo "#define __PLUMED_HAS_RTLD_DEFAULT 1" >>confdefs.h
+      printf "%s\n" "#define __PLUMED_HAS_RTLD_DEFAULT 1" >>confdefs.h
 
       __PLUMED_HAS_RTLD_DEFAULT=yes
     else
-      { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_RTLD_DEFAULT" >&5
-$as_echo "$as_me: WARNING: cannot enable __PLUMED_HAS_RTLD_DEFAULT" >&2;}
+      { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_RTLD_DEFAULT" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable __PLUMED_HAS_RTLD_DEFAULT" >&2;}
       LIBS="$save_LIBS"
     fi
 
@@ -7603,8 +8266,8 @@ if test $subprocess = true ; then
     fi
 
     # check without libraries
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking subprocess without extra libs" >&5
-$as_echo_n "checking subprocess without extra libs... " >&6; }
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking subprocess without extra libs" >&5
+printf %s "checking subprocess without extra libs... " >&6; }
     cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
@@ -7640,22 +8303,24 @@ main ()
 
 
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"
+then :
   found=ok
-          { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-
+          { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+       ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
     if test "$found" = "ko" ; then
       if test "$multiple" = "yes" ; then
-        { $as_echo "$as_me:${as_lineno-$LINENO}: checking subprocess with $all_LIBS" >&5
-$as_echo_n "checking subprocess with $all_LIBS... " >&6; }
+        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking subprocess with $all_LIBS" >&5
+printf %s "checking subprocess with $all_LIBS... " >&6; }
         LIBS="$all_LIBS $LIBS"
         cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
@@ -7692,22 +8357,24 @@ main ()
 
 
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"
+then :
   found=ok
-              { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-
+              { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+           ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
       else
         for testlib in $testlibs
         do
-          { $as_echo "$as_me:${as_lineno-$LINENO}: checking subprocess with -l$testlib" >&5
-$as_echo_n "checking subprocess with -l$testlib... " >&6; }
+          { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking subprocess with -l$testlib" >&5
+printf %s "checking subprocess with -l$testlib... " >&6; }
           LIBS="-l$testlib $LIBS"
           cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
@@ -7744,16 +8411,18 @@ main ()
 
 
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"
+then :
   found=ok
-                { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-
+                { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+           ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
           if test $found = ok ; then
             break
@@ -7764,12 +8433,12 @@ rm -f core conftest.err conftest.$ac_objext \
     fi
 
     if test $found = ok ; then
-      $as_echo "#define __PLUMED_HAS_SUBPROCESS 1" >>confdefs.h
+      printf "%s\n" "#define __PLUMED_HAS_SUBPROCESS 1" >>confdefs.h
 
       __PLUMED_HAS_SUBPROCESS=yes
     else
-      { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_SUBPROCESS" >&5
-$as_echo "$as_me: WARNING: cannot enable __PLUMED_HAS_SUBPROCESS" >&2;}
+      { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_SUBPROCESS" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable __PLUMED_HAS_SUBPROCESS" >&2;}
       LIBS="$save_LIBS"
     fi
 
@@ -7779,120 +8448,129 @@ if test $popen = true ; then
 
     found=ko
     __PLUMED_HAS_POPEN=no
-    ac_fn_cxx_check_header_mongrel "$LINENO" "cstdio" "ac_cv_header_cstdio" "$ac_includes_default"
-if test "x$ac_cv_header_cstdio" = xyes; then :
+    ac_fn_cxx_check_header_compile "$LINENO" "cstdio" "ac_cv_header_cstdio" "$ac_includes_default"
+if test "x$ac_cv_header_cstdio" = xyes
+then :
 
 
   if test "${libsearch}" = true ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing popen" >&5
-$as_echo_n "checking for library containing popen... " >&6; }
-if ${ac_cv_search_popen+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing popen" >&5
+printf %s "checking for library containing popen... " >&6; }
+if test ${ac_cv_search_popen+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char popen ();
+namespace conftest {
+  extern "C" int popen ();
+}
 int
-main ()
+main (void)
 {
-return popen ();
+return conftest::popen ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_popen=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_popen+:} false; then :
+  if test ${ac_cv_search_popen+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_popen+:} false; then :
+if test ${ac_cv_search_popen+y}
+then :
 
-else
-  ac_cv_search_popen=no
+else case e in #(
+  e) ac_cv_search_popen=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_popen" >&5
-$as_echo "$ac_cv_search_popen" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_popen" >&5
+printf "%s\n" "$ac_cv_search_popen" >&6; }
 ac_res=$ac_cv_search_popen
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
 
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing popen" >&5
-$as_echo_n "checking for library containing popen... " >&6; }
-if ${ac_cv_search_popen+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing popen" >&5
+printf %s "checking for library containing popen... " >&6; }
+if test ${ac_cv_search_popen+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char popen ();
+namespace conftest {
+  extern "C" int popen ();
+}
 int
-main ()
+main (void)
 {
-return popen ();
+return conftest::popen ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_popen=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_popen+:} false; then :
+  if test ${ac_cv_search_popen+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_popen+:} false; then :
+if test ${ac_cv_search_popen+y}
+then :
 
-else
-  ac_cv_search_popen=no
+else case e in #(
+  e) ac_cv_search_popen=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_popen" >&5
-$as_echo "$ac_cv_search_popen" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_popen" >&5
+printf "%s\n" "$ac_cv_search_popen" >&6; }
 ac_res=$ac_cv_search_popen
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
@@ -7902,14 +8580,13 @@ fi
 
 fi
 
-
     if test $found = ok ; then
-       $as_echo "#define __PLUMED_HAS_POPEN 1" >>confdefs.h
+       printf "%s\n" "#define __PLUMED_HAS_POPEN 1" >>confdefs.h
 
        __PLUMED_HAS_POPEN=yes
     else
-       { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_POPEN" >&5
-$as_echo "$as_me: WARNING: cannot enable __PLUMED_HAS_POPEN" >&2;}
+       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_POPEN" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable __PLUMED_HAS_POPEN" >&2;}
     fi
 
 fi
@@ -7918,120 +8595,129 @@ if test $execinfo = true ; then
 
     found=ko
     __PLUMED_HAS_EXECINFO=no
-    ac_fn_cxx_check_header_mongrel "$LINENO" "execinfo.h" "ac_cv_header_execinfo_h" "$ac_includes_default"
-if test "x$ac_cv_header_execinfo_h" = xyes; then :
+    ac_fn_cxx_check_header_compile "$LINENO" "execinfo.h" "ac_cv_header_execinfo_h" "$ac_includes_default"
+if test "x$ac_cv_header_execinfo_h" = xyes
+then :
 
 
   if test "${libsearch}" = true ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing backtrace" >&5
-$as_echo_n "checking for library containing backtrace... " >&6; }
-if ${ac_cv_search_backtrace+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing backtrace" >&5
+printf %s "checking for library containing backtrace... " >&6; }
+if test ${ac_cv_search_backtrace+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char backtrace ();
+namespace conftest {
+  extern "C" int backtrace ();
+}
 int
-main ()
+main (void)
 {
-return backtrace ();
+return conftest::backtrace ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_backtrace=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_backtrace+:} false; then :
+  if test ${ac_cv_search_backtrace+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_backtrace+:} false; then :
+if test ${ac_cv_search_backtrace+y}
+then :
 
-else
-  ac_cv_search_backtrace=no
+else case e in #(
+  e) ac_cv_search_backtrace=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_backtrace" >&5
-$as_echo "$ac_cv_search_backtrace" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_backtrace" >&5
+printf "%s\n" "$ac_cv_search_backtrace" >&6; }
 ac_res=$ac_cv_search_backtrace
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
 
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing backtrace" >&5
-$as_echo_n "checking for library containing backtrace... " >&6; }
-if ${ac_cv_search_backtrace+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing backtrace" >&5
+printf %s "checking for library containing backtrace... " >&6; }
+if test ${ac_cv_search_backtrace+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char backtrace ();
+namespace conftest {
+  extern "C" int backtrace ();
+}
 int
-main ()
+main (void)
 {
-return backtrace ();
+return conftest::backtrace ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_backtrace=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_backtrace+:} false; then :
+  if test ${ac_cv_search_backtrace+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_backtrace+:} false; then :
+if test ${ac_cv_search_backtrace+y}
+then :
 
-else
-  ac_cv_search_backtrace=no
+else case e in #(
+  e) ac_cv_search_backtrace=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_backtrace" >&5
-$as_echo "$ac_cv_search_backtrace" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_backtrace" >&5
+printf "%s\n" "$ac_cv_search_backtrace" >&6; }
 ac_res=$ac_cv_search_backtrace
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
@@ -8041,14 +8727,13 @@ fi
 
 fi
 
-
     if test $found = ok ; then
-       $as_echo "#define __PLUMED_HAS_EXECINFO 1" >>confdefs.h
+       printf "%s\n" "#define __PLUMED_HAS_EXECINFO 1" >>confdefs.h
 
        __PLUMED_HAS_EXECINFO=yes
     else
-       { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_EXECINFO" >&5
-$as_echo "$as_me: WARNING: cannot enable __PLUMED_HAS_EXECINFO" >&2;}
+       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_EXECINFO" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable __PLUMED_HAS_EXECINFO" >&2;}
     fi
 
 fi
@@ -8056,120 +8741,129 @@ if test $zlib = true ; then
 
     found=ko
     __PLUMED_HAS_ZLIB=no
-    ac_fn_cxx_check_header_mongrel "$LINENO" "zlib.h" "ac_cv_header_zlib_h" "$ac_includes_default"
-if test "x$ac_cv_header_zlib_h" = xyes; then :
+    ac_fn_cxx_check_header_compile "$LINENO" "zlib.h" "ac_cv_header_zlib_h" "$ac_includes_default"
+if test "x$ac_cv_header_zlib_h" = xyes
+then :
 
 
   if test "${libsearch}" = true ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing gzopen" >&5
-$as_echo_n "checking for library containing gzopen... " >&6; }
-if ${ac_cv_search_gzopen+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing gzopen" >&5
+printf %s "checking for library containing gzopen... " >&6; }
+if test ${ac_cv_search_gzopen+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char gzopen ();
+namespace conftest {
+  extern "C" int gzopen ();
+}
 int
-main ()
+main (void)
 {
-return gzopen ();
+return conftest::gzopen ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' z; do
+for ac_lib in '' z
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_gzopen=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_gzopen+:} false; then :
+  if test ${ac_cv_search_gzopen+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_gzopen+:} false; then :
+if test ${ac_cv_search_gzopen+y}
+then :
 
-else
-  ac_cv_search_gzopen=no
+else case e in #(
+  e) ac_cv_search_gzopen=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_gzopen" >&5
-$as_echo "$ac_cv_search_gzopen" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_gzopen" >&5
+printf "%s\n" "$ac_cv_search_gzopen" >&6; }
 ac_res=$ac_cv_search_gzopen
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
 
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing gzopen" >&5
-$as_echo_n "checking for library containing gzopen... " >&6; }
-if ${ac_cv_search_gzopen+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing gzopen" >&5
+printf %s "checking for library containing gzopen... " >&6; }
+if test ${ac_cv_search_gzopen+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char gzopen ();
+namespace conftest {
+  extern "C" int gzopen ();
+}
 int
-main ()
+main (void)
 {
-return gzopen ();
+return conftest::gzopen ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_gzopen=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_gzopen+:} false; then :
+  if test ${ac_cv_search_gzopen+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_gzopen+:} false; then :
+if test ${ac_cv_search_gzopen+y}
+then :
 
-else
-  ac_cv_search_gzopen=no
+else case e in #(
+  e) ac_cv_search_gzopen=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_gzopen" >&5
-$as_echo "$ac_cv_search_gzopen" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_gzopen" >&5
+printf "%s\n" "$ac_cv_search_gzopen" >&6; }
 ac_res=$ac_cv_search_gzopen
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
@@ -8179,14 +8873,13 @@ fi
 
 fi
 
-
     if test $found = ok ; then
-       $as_echo "#define __PLUMED_HAS_ZLIB 1" >>confdefs.h
+       printf "%s\n" "#define __PLUMED_HAS_ZLIB 1" >>confdefs.h
 
        __PLUMED_HAS_ZLIB=yes
     else
-       { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_ZLIB" >&5
-$as_echo "$as_me: WARNING: cannot enable __PLUMED_HAS_ZLIB" >&2;}
+       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_ZLIB" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable __PLUMED_HAS_ZLIB" >&2;}
     fi
 
 fi
@@ -8195,174 +8888,187 @@ if test $gsl = true ; then
   found=ko
 
   if test "${libsearch}" = true ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing cblas_dgemv" >&5
-$as_echo_n "checking for library containing cblas_dgemv... " >&6; }
-if ${ac_cv_search_cblas_dgemv+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing cblas_dgemv" >&5
+printf %s "checking for library containing cblas_dgemv... " >&6; }
+if test ${ac_cv_search_cblas_dgemv+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char cblas_dgemv ();
+namespace conftest {
+  extern "C" int cblas_dgemv ();
+}
 int
-main ()
+main (void)
 {
-return cblas_dgemv ();
+return conftest::cblas_dgemv ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' gslcblas; do
+for ac_lib in '' gslcblas
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_cblas_dgemv=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_cblas_dgemv+:} false; then :
+  if test ${ac_cv_search_cblas_dgemv+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_cblas_dgemv+:} false; then :
+if test ${ac_cv_search_cblas_dgemv+y}
+then :
 
-else
-  ac_cv_search_cblas_dgemv=no
+else case e in #(
+  e) ac_cv_search_cblas_dgemv=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_cblas_dgemv" >&5
-$as_echo "$ac_cv_search_cblas_dgemv" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_cblas_dgemv" >&5
+printf "%s\n" "$ac_cv_search_cblas_dgemv" >&6; }
 ac_res=$ac_cv_search_cblas_dgemv
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
 
-    ac_fn_cxx_check_header_mongrel "$LINENO" "gsl/gsl_vector.h" "ac_cv_header_gsl_gsl_vector_h" "$ac_includes_default"
-if test "x$ac_cv_header_gsl_gsl_vector_h" = xyes; then :
+    ac_fn_cxx_check_header_compile "$LINENO" "gsl/gsl_vector.h" "ac_cv_header_gsl_gsl_vector_h" "$ac_includes_default"
+if test "x$ac_cv_header_gsl_gsl_vector_h" = xyes
+then :
 
 
   if test "${libsearch}" = true ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing gsl_vector_alloc" >&5
-$as_echo_n "checking for library containing gsl_vector_alloc... " >&6; }
-if ${ac_cv_search_gsl_vector_alloc+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing gsl_vector_alloc" >&5
+printf %s "checking for library containing gsl_vector_alloc... " >&6; }
+if test ${ac_cv_search_gsl_vector_alloc+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char gsl_vector_alloc ();
+namespace conftest {
+  extern "C" int gsl_vector_alloc ();
+}
 int
-main ()
+main (void)
 {
-return gsl_vector_alloc ();
+return conftest::gsl_vector_alloc ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' gsl; do
+for ac_lib in '' gsl
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_gsl_vector_alloc=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_gsl_vector_alloc+:} false; then :
+  if test ${ac_cv_search_gsl_vector_alloc+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_gsl_vector_alloc+:} false; then :
+if test ${ac_cv_search_gsl_vector_alloc+y}
+then :
 
-else
-  ac_cv_search_gsl_vector_alloc=no
+else case e in #(
+  e) ac_cv_search_gsl_vector_alloc=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_gsl_vector_alloc" >&5
-$as_echo "$ac_cv_search_gsl_vector_alloc" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_gsl_vector_alloc" >&5
+printf "%s\n" "$ac_cv_search_gsl_vector_alloc" >&6; }
 ac_res=$ac_cv_search_gsl_vector_alloc
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
 
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing gsl_vector_alloc" >&5
-$as_echo_n "checking for library containing gsl_vector_alloc... " >&6; }
-if ${ac_cv_search_gsl_vector_alloc+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing gsl_vector_alloc" >&5
+printf %s "checking for library containing gsl_vector_alloc... " >&6; }
+if test ${ac_cv_search_gsl_vector_alloc+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char gsl_vector_alloc ();
+namespace conftest {
+  extern "C" int gsl_vector_alloc ();
+}
 int
-main ()
+main (void)
 {
-return gsl_vector_alloc ();
+return conftest::gsl_vector_alloc ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_gsl_vector_alloc=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_gsl_vector_alloc+:} false; then :
+  if test ${ac_cv_search_gsl_vector_alloc+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_gsl_vector_alloc+:} false; then :
+if test ${ac_cv_search_gsl_vector_alloc+y}
+then :
 
-else
-  ac_cv_search_gsl_vector_alloc=no
+else case e in #(
+  e) ac_cv_search_gsl_vector_alloc=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_gsl_vector_alloc" >&5
-$as_echo "$ac_cv_search_gsl_vector_alloc" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_gsl_vector_alloc" >&5
+printf "%s\n" "$ac_cv_search_gsl_vector_alloc" >&6; }
 ac_res=$ac_cv_search_gsl_vector_alloc
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
@@ -8373,178 +9079,190 @@ fi
 fi
 
 
-
 fi
 
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing cblas_dgemv" >&5
-$as_echo_n "checking for library containing cblas_dgemv... " >&6; }
-if ${ac_cv_search_cblas_dgemv+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing cblas_dgemv" >&5
+printf %s "checking for library containing cblas_dgemv... " >&6; }
+if test ${ac_cv_search_cblas_dgemv+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char cblas_dgemv ();
+namespace conftest {
+  extern "C" int cblas_dgemv ();
+}
 int
-main ()
+main (void)
 {
-return cblas_dgemv ();
+return conftest::cblas_dgemv ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_cblas_dgemv=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_cblas_dgemv+:} false; then :
+  if test ${ac_cv_search_cblas_dgemv+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_cblas_dgemv+:} false; then :
+if test ${ac_cv_search_cblas_dgemv+y}
+then :
 
-else
-  ac_cv_search_cblas_dgemv=no
+else case e in #(
+  e) ac_cv_search_cblas_dgemv=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_cblas_dgemv" >&5
-$as_echo "$ac_cv_search_cblas_dgemv" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_cblas_dgemv" >&5
+printf "%s\n" "$ac_cv_search_cblas_dgemv" >&6; }
 ac_res=$ac_cv_search_cblas_dgemv
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
 
-    ac_fn_cxx_check_header_mongrel "$LINENO" "gsl/gsl_vector.h" "ac_cv_header_gsl_gsl_vector_h" "$ac_includes_default"
-if test "x$ac_cv_header_gsl_gsl_vector_h" = xyes; then :
+    ac_fn_cxx_check_header_compile "$LINENO" "gsl/gsl_vector.h" "ac_cv_header_gsl_gsl_vector_h" "$ac_includes_default"
+if test "x$ac_cv_header_gsl_gsl_vector_h" = xyes
+then :
 
 
   if test "${libsearch}" = true ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing gsl_vector_alloc" >&5
-$as_echo_n "checking for library containing gsl_vector_alloc... " >&6; }
-if ${ac_cv_search_gsl_vector_alloc+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing gsl_vector_alloc" >&5
+printf %s "checking for library containing gsl_vector_alloc... " >&6; }
+if test ${ac_cv_search_gsl_vector_alloc+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char gsl_vector_alloc ();
+namespace conftest {
+  extern "C" int gsl_vector_alloc ();
+}
 int
-main ()
+main (void)
 {
-return gsl_vector_alloc ();
+return conftest::gsl_vector_alloc ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' gsl; do
+for ac_lib in '' gsl
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_gsl_vector_alloc=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_gsl_vector_alloc+:} false; then :
+  if test ${ac_cv_search_gsl_vector_alloc+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_gsl_vector_alloc+:} false; then :
+if test ${ac_cv_search_gsl_vector_alloc+y}
+then :
 
-else
-  ac_cv_search_gsl_vector_alloc=no
+else case e in #(
+  e) ac_cv_search_gsl_vector_alloc=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_gsl_vector_alloc" >&5
-$as_echo "$ac_cv_search_gsl_vector_alloc" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_gsl_vector_alloc" >&5
+printf "%s\n" "$ac_cv_search_gsl_vector_alloc" >&6; }
 ac_res=$ac_cv_search_gsl_vector_alloc
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
 
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing gsl_vector_alloc" >&5
-$as_echo_n "checking for library containing gsl_vector_alloc... " >&6; }
-if ${ac_cv_search_gsl_vector_alloc+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing gsl_vector_alloc" >&5
+printf %s "checking for library containing gsl_vector_alloc... " >&6; }
+if test ${ac_cv_search_gsl_vector_alloc+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char gsl_vector_alloc ();
+namespace conftest {
+  extern "C" int gsl_vector_alloc ();
+}
 int
-main ()
+main (void)
 {
-return gsl_vector_alloc ();
+return conftest::gsl_vector_alloc ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_gsl_vector_alloc=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_gsl_vector_alloc+:} false; then :
+  if test ${ac_cv_search_gsl_vector_alloc+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_gsl_vector_alloc+:} false; then :
+if test ${ac_cv_search_gsl_vector_alloc+y}
+then :
 
-else
-  ac_cv_search_gsl_vector_alloc=no
+else case e in #(
+  e) ac_cv_search_gsl_vector_alloc=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_gsl_vector_alloc" >&5
-$as_echo "$ac_cv_search_gsl_vector_alloc" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_gsl_vector_alloc" >&5
+printf "%s\n" "$ac_cv_search_gsl_vector_alloc" >&6; }
 ac_res=$ac_cv_search_gsl_vector_alloc
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
@@ -8555,17 +9273,16 @@ fi
 fi
 
 
-
 fi
 
   fi
 
   if test $found = ok ; then
-    $as_echo "#define __PLUMED_HAS_GSL 1" >>confdefs.h
+    printf "%s\n" "#define __PLUMED_HAS_GSL 1" >>confdefs.h
 
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_GSL" >&5
-$as_echo "$as_me: WARNING: cannot enable __PLUMED_HAS_GSL" >&2;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_GSL" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable __PLUMED_HAS_GSL" >&2;}
   fi
 fi
 
@@ -8593,8 +9310,8 @@ if test $boost_graph = true ; then
     fi
 
     # check without libraries
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking boost graph without extra libs" >&5
-$as_echo_n "checking boost graph without extra libs... " >&6; }
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking boost graph without extra libs" >&5
+printf %s "checking boost graph without extra libs... " >&6; }
     cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
@@ -8609,22 +9326,24 @@ main ()
 }
 
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"
+then :
   found=ok
-          { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-
+          { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+       ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
     if test "$found" = "ko" ; then
       if test "$multiple" = "yes" ; then
-        { $as_echo "$as_me:${as_lineno-$LINENO}: checking boost graph with $all_LIBS" >&5
-$as_echo_n "checking boost graph with $all_LIBS... " >&6; }
+        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking boost graph with $all_LIBS" >&5
+printf %s "checking boost graph with $all_LIBS... " >&6; }
         LIBS="$all_LIBS $LIBS"
         cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
@@ -8640,22 +9359,24 @@ main ()
 }
 
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"
+then :
   found=ok
-              { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-
+              { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+           ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
       else
         for testlib in $testlibs
         do
-          { $as_echo "$as_me:${as_lineno-$LINENO}: checking boost graph with -l$testlib" >&5
-$as_echo_n "checking boost graph with -l$testlib... " >&6; }
+          { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking boost graph with -l$testlib" >&5
+printf %s "checking boost graph with -l$testlib... " >&6; }
           LIBS="-l$testlib $LIBS"
           cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
@@ -8671,16 +9392,18 @@ main ()
 }
 
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"
+then :
   found=ok
-                { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-
+                { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+           ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
           if test $found = ok ; then
             break
@@ -8691,12 +9414,12 @@ rm -f core conftest.err conftest.$ac_objext \
     fi
 
     if test $found = ok ; then
-      $as_echo "#define __PLUMED_HAS_BOOST_GRAPH 1" >>confdefs.h
+      printf "%s\n" "#define __PLUMED_HAS_BOOST_GRAPH 1" >>confdefs.h
 
       __PLUMED_HAS_BOOST_GRAPH=yes
     else
-      { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_BOOST_GRAPH" >&5
-$as_echo "$as_me: WARNING: cannot enable __PLUMED_HAS_BOOST_GRAPH" >&2;}
+      { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_BOOST_GRAPH" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable __PLUMED_HAS_BOOST_GRAPH" >&2;}
       LIBS="$save_LIBS"
     fi
 
@@ -8726,8 +9449,8 @@ if test $boost_serialization = true ; then
     fi
 
     # check without libraries
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking boost serialization without extra libs" >&5
-$as_echo_n "checking boost serialization without extra libs... " >&6; }
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking boost serialization without extra libs" >&5
+printf %s "checking boost serialization without extra libs... " >&6; }
     cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
@@ -8740,22 +9463,24 @@ int main() {
 }
 
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"
+then :
   found=ok
-          { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-
+          { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+       ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
     if test "$found" = "ko" ; then
       if test "$multiple" = "yes" ; then
-        { $as_echo "$as_me:${as_lineno-$LINENO}: checking boost serialization with $all_LIBS" >&5
-$as_echo_n "checking boost serialization with $all_LIBS... " >&6; }
+        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking boost serialization with $all_LIBS" >&5
+printf %s "checking boost serialization with $all_LIBS... " >&6; }
         LIBS="$all_LIBS $LIBS"
         cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
@@ -8769,22 +9494,24 @@ int main() {
 }
 
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"
+then :
   found=ok
-              { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-
+              { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+           ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
       else
         for testlib in $testlibs
         do
-          { $as_echo "$as_me:${as_lineno-$LINENO}: checking boost serialization with -l$testlib" >&5
-$as_echo_n "checking boost serialization with -l$testlib... " >&6; }
+          { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking boost serialization with -l$testlib" >&5
+printf %s "checking boost serialization with -l$testlib... " >&6; }
           LIBS="-l$testlib $LIBS"
           cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
@@ -8798,16 +9525,18 @@ int main() {
 }
 
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"
+then :
   found=ok
-                { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-
+                { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+           ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
           if test $found = ok ; then
             break
@@ -8818,12 +9547,12 @@ rm -f core conftest.err conftest.$ac_objext \
     fi
 
     if test $found = ok ; then
-      $as_echo "#define __PLUMED_HAS_BOOST_SERIALIZATION 1" >>confdefs.h
+      printf "%s\n" "#define __PLUMED_HAS_BOOST_SERIALIZATION 1" >>confdefs.h
 
       __PLUMED_HAS_BOOST_SERIALIZATION=yes
     else
-      { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_BOOST_SERIALIZATION" >&5
-$as_echo "$as_me: WARNING: cannot enable __PLUMED_HAS_BOOST_SERIALIZATION" >&2;}
+      { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_BOOST_SERIALIZATION" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable __PLUMED_HAS_BOOST_SERIALIZATION" >&2;}
       LIBS="$save_LIBS"
     fi
 
@@ -8834,120 +9563,129 @@ if test $fftw = true ; then
 
     found=ko
     __PLUMED_HAS_FFTW=no
-    ac_fn_cxx_check_header_mongrel "$LINENO" "fftw3.h" "ac_cv_header_fftw3_h" "$ac_includes_default"
-if test "x$ac_cv_header_fftw3_h" = xyes; then :
+    ac_fn_cxx_check_header_compile "$LINENO" "fftw3.h" "ac_cv_header_fftw3_h" "$ac_includes_default"
+if test "x$ac_cv_header_fftw3_h" = xyes
+then :
 
 
   if test "${libsearch}" = true ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing fftw_execute" >&5
-$as_echo_n "checking for library containing fftw_execute... " >&6; }
-if ${ac_cv_search_fftw_execute+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing fftw_execute" >&5
+printf %s "checking for library containing fftw_execute... " >&6; }
+if test ${ac_cv_search_fftw_execute+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char fftw_execute ();
+namespace conftest {
+  extern "C" int fftw_execute ();
+}
 int
-main ()
+main (void)
 {
-return fftw_execute ();
+return conftest::fftw_execute ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' fftw3; do
+for ac_lib in '' fftw3
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_fftw_execute=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_fftw_execute+:} false; then :
+  if test ${ac_cv_search_fftw_execute+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_fftw_execute+:} false; then :
+if test ${ac_cv_search_fftw_execute+y}
+then :
 
-else
-  ac_cv_search_fftw_execute=no
+else case e in #(
+  e) ac_cv_search_fftw_execute=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_fftw_execute" >&5
-$as_echo "$ac_cv_search_fftw_execute" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_fftw_execute" >&5
+printf "%s\n" "$ac_cv_search_fftw_execute" >&6; }
 ac_res=$ac_cv_search_fftw_execute
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
 
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing fftw_execute" >&5
-$as_echo_n "checking for library containing fftw_execute... " >&6; }
-if ${ac_cv_search_fftw_execute+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing fftw_execute" >&5
+printf %s "checking for library containing fftw_execute... " >&6; }
+if test ${ac_cv_search_fftw_execute+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char fftw_execute ();
+namespace conftest {
+  extern "C" int fftw_execute ();
+}
 int
-main ()
+main (void)
 {
-return fftw_execute ();
+return conftest::fftw_execute ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_fftw_execute=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_fftw_execute+:} false; then :
+  if test ${ac_cv_search_fftw_execute+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_fftw_execute+:} false; then :
+if test ${ac_cv_search_fftw_execute+y}
+then :
 
-else
-  ac_cv_search_fftw_execute=no
+else case e in #(
+  e) ac_cv_search_fftw_execute=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_fftw_execute" >&5
-$as_echo "$ac_cv_search_fftw_execute" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_fftw_execute" >&5
+printf "%s\n" "$ac_cv_search_fftw_execute" >&6; }
 ac_res=$ac_cv_search_fftw_execute
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
@@ -8957,14 +9695,13 @@ fi
 
 fi
 
-
     if test $found = ok ; then
-       $as_echo "#define __PLUMED_HAS_FFTW 1" >>confdefs.h
+       printf "%s\n" "#define __PLUMED_HAS_FFTW 1" >>confdefs.h
 
        __PLUMED_HAS_FFTW=yes
     else
-       { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_FFTW" >&5
-$as_echo "$as_me: WARNING: cannot enable __PLUMED_HAS_FFTW" >&2;}
+       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_FFTW" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable __PLUMED_HAS_FFTW" >&2;}
     fi
 
 fi
@@ -8987,38 +9724,44 @@ if test -z "$PYTHON_BIN" ; then
 do
   # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
-$as_echo_n "checking for $ac_word... " >&6; }
-if ${ac_cv_prog_PYTHON_BIN+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  if test -n "$PYTHON_BIN"; then
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+printf %s "checking for $ac_word... " >&6; }
+if test ${ac_cv_prog_PYTHON_BIN+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) if test -n "$PYTHON_BIN"; then
   ac_cv_prog_PYTHON_BIN="$PYTHON_BIN" # Let the user override the test.
 else
 as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
 for as_dir in $PATH
 do
   IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
+  case $as_dir in #(((
+    '') as_dir=./ ;;
+    */) ;;
+    *) as_dir=$as_dir/ ;;
+  esac
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+  if as_fn_executable_p "$as_dir$ac_word$ac_exec_ext"; then
     ac_cv_prog_PYTHON_BIN="$ac_prog"
-    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    printf "%s\n" "$as_me:${as_lineno-$LINENO}: found $as_dir$ac_word$ac_exec_ext" >&5
     break 2
   fi
 done
   done
 IFS=$as_save_IFS
 
-fi
+fi ;;
+esac
 fi
 PYTHON_BIN=$ac_cv_prog_PYTHON_BIN
 if test -n "$PYTHON_BIN"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $PYTHON_BIN" >&5
-$as_echo "$PYTHON_BIN" >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $PYTHON_BIN" >&5
+printf "%s\n" "$PYTHON_BIN" >&6; }
 else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
 fi
 
 
@@ -9027,11 +9770,11 @@ done
 
 fi
 if test -n "$PYTHON_BIN" ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: Python executable is $PYTHON_BIN" >&5
-$as_echo "$as_me: Python executable is $PYTHON_BIN" >&6;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Python executable is $PYTHON_BIN" >&5
+printf "%s\n" "$as_me: Python executable is $PYTHON_BIN" >&6;}
   if test $pycv = true  ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking pycv: support for required python modules (python3, pybind11, numpy)" >&5
-$as_echo_n "checking pycv: support for required python modules (python3, pybind11, numpy)... " >&6; }
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking pycv: support for required python modules (python3, pybind11, numpy)" >&5
+printf %s "checking pycv: support for required python modules (python3, pybind11, numpy)... " >&6; }
   testimport="
 import numpy
 import pybind11
@@ -9043,35 +9786,35 @@ import pybind11
        python_config=python${pyver}-config
 
        if ${python_config} --ldflags --embed 1>/dev/null 2>/dev/null ;then
-          { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
+          { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
           PYBIND11_CFLAGS="$($PYTHON_BIN -m pybind11 --includes) -fvisibility=hidden"
           PYTHON_CFLAGS=$(${python_config} --cflags --embed)
           PYTHON_LDFLAGS=$(${python_config} --ldflags --embed)
           #TODO: conda_fixup
           PLUMED_CAN_PYCV=yes
         else
-          { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-          { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable pycv" >&5
-$as_echo "$as_me: WARNING: cannot enable pycv" >&2;}
-          { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: \"PyCV needs python to be embeddable, please rebuild python\"" >&5
-$as_echo "$as_me: WARNING: \"PyCV needs python to be embeddable, please rebuild python\"" >&2;}
+          { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+          { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable pycv" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable pycv" >&2;}
+          { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: \"PyCV needs python to be embeddable, please rebuild python\"" >&5
+printf "%s\n" "$as_me: WARNING: \"PyCV needs python to be embeddable, please rebuild python\"" >&2;}
        fi
     else
-       { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-       { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable pycv" >&5
-$as_echo "$as_me: WARNING: cannot enable pycv" >&2;}
+       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable pycv" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable pycv" >&2;}
     fi
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable pycv" >&5
-$as_echo "$as_me: WARNING: cannot enable pycv" >&2;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable pycv" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable pycv" >&2;}
   fi
 
   if test $python = true  ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking python wrapper: support for required python modules (python3, setuptools, cython)" >&5
-$as_echo_n "checking python wrapper: support for required python modules (python3, setuptools, cython)... " >&6; }
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking python wrapper: support for required python modules (python3, setuptools, cython)" >&5
+printf %s "checking python wrapper: support for required python modules (python3, setuptools, cython)... " >&6; }
     testimport="
 from setuptools import setup
 from setuptools import Extension
@@ -9081,20 +9824,20 @@ if sys.version_info < (3,):
     raise ImportError('PLUMED>= 2.6 only supports Python 3')
 "
     if echo "$testimport" | "$PYTHON_BIN" 1>/dev/null 2>/dev/null;  then
-       { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-       $as_echo "#define __PLUMED_HAS_PYTHON 1" >>confdefs.h
+       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+       printf "%s\n" "#define __PLUMED_HAS_PYTHON 1" >>confdefs.h
 
        CYTHON_FOUND=yes
     else
-       { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-       { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable python interface" >&5
-$as_echo "$as_me: WARNING: cannot enable python interface" >&2;}
+       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable python interface" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable python interface" >&2;}
     fi
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable python interface" >&5
-$as_echo "$as_me: WARNING: cannot enable python interface" >&2;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable python interface" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable python interface" >&2;}
   fi
 fi
 
@@ -9107,120 +9850,129 @@ if test "$af_ocl" = true ; then
 
     found=ko
     __PLUMED_HAS_ARRAYFIRE=no
-    ac_fn_cxx_check_header_mongrel "$LINENO" "arrayfire.h" "ac_cv_header_arrayfire_h" "$ac_includes_default"
-if test "x$ac_cv_header_arrayfire_h" = xyes; then :
+    ac_fn_cxx_check_header_compile "$LINENO" "arrayfire.h" "ac_cv_header_arrayfire_h" "$ac_includes_default"
+if test "x$ac_cv_header_arrayfire_h" = xyes
+then :
 
 
   if test "${libsearch}" = true ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing af_is_double" >&5
-$as_echo_n "checking for library containing af_is_double... " >&6; }
-if ${ac_cv_search_af_is_double+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing af_is_double" >&5
+printf %s "checking for library containing af_is_double... " >&6; }
+if test ${ac_cv_search_af_is_double+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char af_is_double ();
+namespace conftest {
+  extern "C" int af_is_double ();
+}
 int
-main ()
+main (void)
 {
-return af_is_double ();
+return conftest::af_is_double ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' afopencl; do
+for ac_lib in '' afopencl
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_af_is_double=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_af_is_double+:} false; then :
+  if test ${ac_cv_search_af_is_double+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_af_is_double+:} false; then :
+if test ${ac_cv_search_af_is_double+y}
+then :
 
-else
-  ac_cv_search_af_is_double=no
+else case e in #(
+  e) ac_cv_search_af_is_double=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_af_is_double" >&5
-$as_echo "$ac_cv_search_af_is_double" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_af_is_double" >&5
+printf "%s\n" "$ac_cv_search_af_is_double" >&6; }
 ac_res=$ac_cv_search_af_is_double
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
 
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing af_is_double" >&5
-$as_echo_n "checking for library containing af_is_double... " >&6; }
-if ${ac_cv_search_af_is_double+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing af_is_double" >&5
+printf %s "checking for library containing af_is_double... " >&6; }
+if test ${ac_cv_search_af_is_double+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char af_is_double ();
+namespace conftest {
+  extern "C" int af_is_double ();
+}
 int
-main ()
+main (void)
 {
-return af_is_double ();
+return conftest::af_is_double ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_af_is_double=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_af_is_double+:} false; then :
+  if test ${ac_cv_search_af_is_double+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_af_is_double+:} false; then :
+if test ${ac_cv_search_af_is_double+y}
+then :
 
-else
-  ac_cv_search_af_is_double=no
+else case e in #(
+  e) ac_cv_search_af_is_double=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_af_is_double" >&5
-$as_echo "$ac_cv_search_af_is_double" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_af_is_double" >&5
+printf "%s\n" "$ac_cv_search_af_is_double" >&6; }
 ac_res=$ac_cv_search_af_is_double
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
@@ -9230,133 +9982,141 @@ fi
 
 fi
 
-
     if test $found = ok ; then
-       $as_echo "#define __PLUMED_HAS_ARRAYFIRE 1" >>confdefs.h
+       printf "%s\n" "#define __PLUMED_HAS_ARRAYFIRE 1" >>confdefs.h
 
        __PLUMED_HAS_ARRAYFIRE=yes
     else
-       { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_ARRAYFIRE" >&5
-$as_echo "$as_me: WARNING: cannot enable __PLUMED_HAS_ARRAYFIRE" >&2;}
+       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_ARRAYFIRE" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable __PLUMED_HAS_ARRAYFIRE" >&2;}
     fi
 
 
     found=ko
     __PLUMED_HAS_ARRAYFIRE_OCL=no
-    ac_fn_cxx_check_header_mongrel "$LINENO" "arrayfire.h" "ac_cv_header_arrayfire_h" "$ac_includes_default"
-if test "x$ac_cv_header_arrayfire_h" = xyes; then :
+    ac_fn_cxx_check_header_compile "$LINENO" "arrayfire.h" "ac_cv_header_arrayfire_h" "$ac_includes_default"
+if test "x$ac_cv_header_arrayfire_h" = xyes
+then :
 
 
   if test "${libsearch}" = true ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing af_is_double" >&5
-$as_echo_n "checking for library containing af_is_double... " >&6; }
-if ${ac_cv_search_af_is_double+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing af_is_double" >&5
+printf %s "checking for library containing af_is_double... " >&6; }
+if test ${ac_cv_search_af_is_double+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char af_is_double ();
+namespace conftest {
+  extern "C" int af_is_double ();
+}
 int
-main ()
+main (void)
 {
-return af_is_double ();
+return conftest::af_is_double ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' afopencl; do
+for ac_lib in '' afopencl
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_af_is_double=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_af_is_double+:} false; then :
+  if test ${ac_cv_search_af_is_double+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_af_is_double+:} false; then :
+if test ${ac_cv_search_af_is_double+y}
+then :
 
-else
-  ac_cv_search_af_is_double=no
+else case e in #(
+  e) ac_cv_search_af_is_double=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_af_is_double" >&5
-$as_echo "$ac_cv_search_af_is_double" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_af_is_double" >&5
+printf "%s\n" "$ac_cv_search_af_is_double" >&6; }
 ac_res=$ac_cv_search_af_is_double
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
 
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing af_is_double" >&5
-$as_echo_n "checking for library containing af_is_double... " >&6; }
-if ${ac_cv_search_af_is_double+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing af_is_double" >&5
+printf %s "checking for library containing af_is_double... " >&6; }
+if test ${ac_cv_search_af_is_double+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char af_is_double ();
+namespace conftest {
+  extern "C" int af_is_double ();
+}
 int
-main ()
+main (void)
 {
-return af_is_double ();
+return conftest::af_is_double ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_af_is_double=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_af_is_double+:} false; then :
+  if test ${ac_cv_search_af_is_double+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_af_is_double+:} false; then :
+if test ${ac_cv_search_af_is_double+y}
+then :
 
-else
-  ac_cv_search_af_is_double=no
+else case e in #(
+  e) ac_cv_search_af_is_double=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_af_is_double" >&5
-$as_echo "$ac_cv_search_af_is_double" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_af_is_double" >&5
+printf "%s\n" "$ac_cv_search_af_is_double" >&6; }
 ac_res=$ac_cv_search_af_is_double
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
@@ -9366,14 +10126,13 @@ fi
 
 fi
 
-
     if test $found = ok ; then
-       $as_echo "#define __PLUMED_HAS_ARRAYFIRE_OCL 1" >>confdefs.h
+       printf "%s\n" "#define __PLUMED_HAS_ARRAYFIRE_OCL 1" >>confdefs.h
 
        __PLUMED_HAS_ARRAYFIRE_OCL=yes
     else
-       { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_ARRAYFIRE_OCL" >&5
-$as_echo "$as_me: WARNING: cannot enable __PLUMED_HAS_ARRAYFIRE_OCL" >&2;}
+       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_ARRAYFIRE_OCL" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable __PLUMED_HAS_ARRAYFIRE_OCL" >&2;}
     fi
 
 fi
@@ -9381,120 +10140,129 @@ if test "$af_cuda" = true ; then
 
     found=ko
     __PLUMED_HAS_ARRAYFIRE=no
-    ac_fn_cxx_check_header_mongrel "$LINENO" "arrayfire.h" "ac_cv_header_arrayfire_h" "$ac_includes_default"
-if test "x$ac_cv_header_arrayfire_h" = xyes; then :
+    ac_fn_cxx_check_header_compile "$LINENO" "arrayfire.h" "ac_cv_header_arrayfire_h" "$ac_includes_default"
+if test "x$ac_cv_header_arrayfire_h" = xyes
+then :
 
 
   if test "${libsearch}" = true ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing af_is_double" >&5
-$as_echo_n "checking for library containing af_is_double... " >&6; }
-if ${ac_cv_search_af_is_double+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing af_is_double" >&5
+printf %s "checking for library containing af_is_double... " >&6; }
+if test ${ac_cv_search_af_is_double+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char af_is_double ();
+namespace conftest {
+  extern "C" int af_is_double ();
+}
 int
-main ()
+main (void)
 {
-return af_is_double ();
+return conftest::af_is_double ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' afcuda; do
+for ac_lib in '' afcuda
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_af_is_double=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_af_is_double+:} false; then :
+  if test ${ac_cv_search_af_is_double+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_af_is_double+:} false; then :
+if test ${ac_cv_search_af_is_double+y}
+then :
 
-else
-  ac_cv_search_af_is_double=no
+else case e in #(
+  e) ac_cv_search_af_is_double=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_af_is_double" >&5
-$as_echo "$ac_cv_search_af_is_double" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_af_is_double" >&5
+printf "%s\n" "$ac_cv_search_af_is_double" >&6; }
 ac_res=$ac_cv_search_af_is_double
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
 
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing af_is_double" >&5
-$as_echo_n "checking for library containing af_is_double... " >&6; }
-if ${ac_cv_search_af_is_double+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing af_is_double" >&5
+printf %s "checking for library containing af_is_double... " >&6; }
+if test ${ac_cv_search_af_is_double+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char af_is_double ();
+namespace conftest {
+  extern "C" int af_is_double ();
+}
 int
-main ()
+main (void)
 {
-return af_is_double ();
+return conftest::af_is_double ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_af_is_double=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_af_is_double+:} false; then :
+  if test ${ac_cv_search_af_is_double+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_af_is_double+:} false; then :
+if test ${ac_cv_search_af_is_double+y}
+then :
 
-else
-  ac_cv_search_af_is_double=no
+else case e in #(
+  e) ac_cv_search_af_is_double=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_af_is_double" >&5
-$as_echo "$ac_cv_search_af_is_double" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_af_is_double" >&5
+printf "%s\n" "$ac_cv_search_af_is_double" >&6; }
 ac_res=$ac_cv_search_af_is_double
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
@@ -9504,133 +10272,141 @@ fi
 
 fi
 
-
     if test $found = ok ; then
-       $as_echo "#define __PLUMED_HAS_ARRAYFIRE 1" >>confdefs.h
+       printf "%s\n" "#define __PLUMED_HAS_ARRAYFIRE 1" >>confdefs.h
 
        __PLUMED_HAS_ARRAYFIRE=yes
     else
-       { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_ARRAYFIRE" >&5
-$as_echo "$as_me: WARNING: cannot enable __PLUMED_HAS_ARRAYFIRE" >&2;}
+       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_ARRAYFIRE" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable __PLUMED_HAS_ARRAYFIRE" >&2;}
     fi
 
 
     found=ko
     __PLUMED_HAS_ARRAYFIRE_CUDA=no
-    ac_fn_cxx_check_header_mongrel "$LINENO" "arrayfire.h" "ac_cv_header_arrayfire_h" "$ac_includes_default"
-if test "x$ac_cv_header_arrayfire_h" = xyes; then :
+    ac_fn_cxx_check_header_compile "$LINENO" "arrayfire.h" "ac_cv_header_arrayfire_h" "$ac_includes_default"
+if test "x$ac_cv_header_arrayfire_h" = xyes
+then :
 
 
   if test "${libsearch}" = true ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing af_is_double" >&5
-$as_echo_n "checking for library containing af_is_double... " >&6; }
-if ${ac_cv_search_af_is_double+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing af_is_double" >&5
+printf %s "checking for library containing af_is_double... " >&6; }
+if test ${ac_cv_search_af_is_double+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char af_is_double ();
+namespace conftest {
+  extern "C" int af_is_double ();
+}
 int
-main ()
+main (void)
 {
-return af_is_double ();
+return conftest::af_is_double ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' afcuda; do
+for ac_lib in '' afcuda
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_af_is_double=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_af_is_double+:} false; then :
+  if test ${ac_cv_search_af_is_double+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_af_is_double+:} false; then :
+if test ${ac_cv_search_af_is_double+y}
+then :
 
-else
-  ac_cv_search_af_is_double=no
+else case e in #(
+  e) ac_cv_search_af_is_double=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_af_is_double" >&5
-$as_echo "$ac_cv_search_af_is_double" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_af_is_double" >&5
+printf "%s\n" "$ac_cv_search_af_is_double" >&6; }
 ac_res=$ac_cv_search_af_is_double
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
 
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing af_is_double" >&5
-$as_echo_n "checking for library containing af_is_double... " >&6; }
-if ${ac_cv_search_af_is_double+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing af_is_double" >&5
+printf %s "checking for library containing af_is_double... " >&6; }
+if test ${ac_cv_search_af_is_double+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char af_is_double ();
+namespace conftest {
+  extern "C" int af_is_double ();
+}
 int
-main ()
+main (void)
 {
-return af_is_double ();
+return conftest::af_is_double ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_af_is_double=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_af_is_double+:} false; then :
+  if test ${ac_cv_search_af_is_double+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_af_is_double+:} false; then :
+if test ${ac_cv_search_af_is_double+y}
+then :
 
-else
-  ac_cv_search_af_is_double=no
+else case e in #(
+  e) ac_cv_search_af_is_double=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_af_is_double" >&5
-$as_echo "$ac_cv_search_af_is_double" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_af_is_double" >&5
+printf "%s\n" "$ac_cv_search_af_is_double" >&6; }
 ac_res=$ac_cv_search_af_is_double
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
@@ -9640,14 +10416,13 @@ fi
 
 fi
 
-
     if test $found = ok ; then
-       $as_echo "#define __PLUMED_HAS_ARRAYFIRE_CUDA 1" >>confdefs.h
+       printf "%s\n" "#define __PLUMED_HAS_ARRAYFIRE_CUDA 1" >>confdefs.h
 
        __PLUMED_HAS_ARRAYFIRE_CUDA=yes
     else
-       { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_ARRAYFIRE_CUDA" >&5
-$as_echo "$as_me: WARNING: cannot enable __PLUMED_HAS_ARRAYFIRE_CUDA" >&2;}
+       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_ARRAYFIRE_CUDA" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable __PLUMED_HAS_ARRAYFIRE_CUDA" >&2;}
     fi
 
 fi
@@ -9655,120 +10430,129 @@ if test "$af_cpu" = true ; then
 
     found=ko
     __PLUMED_HAS_ARRAYFIRE=no
-    ac_fn_cxx_check_header_mongrel "$LINENO" "arrayfire.h" "ac_cv_header_arrayfire_h" "$ac_includes_default"
-if test "x$ac_cv_header_arrayfire_h" = xyes; then :
+    ac_fn_cxx_check_header_compile "$LINENO" "arrayfire.h" "ac_cv_header_arrayfire_h" "$ac_includes_default"
+if test "x$ac_cv_header_arrayfire_h" = xyes
+then :
 
 
   if test "${libsearch}" = true ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing af_is_double" >&5
-$as_echo_n "checking for library containing af_is_double... " >&6; }
-if ${ac_cv_search_af_is_double+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing af_is_double" >&5
+printf %s "checking for library containing af_is_double... " >&6; }
+if test ${ac_cv_search_af_is_double+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char af_is_double ();
+namespace conftest {
+  extern "C" int af_is_double ();
+}
 int
-main ()
+main (void)
 {
-return af_is_double ();
+return conftest::af_is_double ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' afcpu; do
+for ac_lib in '' afcpu
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_af_is_double=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_af_is_double+:} false; then :
+  if test ${ac_cv_search_af_is_double+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_af_is_double+:} false; then :
+if test ${ac_cv_search_af_is_double+y}
+then :
 
-else
-  ac_cv_search_af_is_double=no
+else case e in #(
+  e) ac_cv_search_af_is_double=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_af_is_double" >&5
-$as_echo "$ac_cv_search_af_is_double" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_af_is_double" >&5
+printf "%s\n" "$ac_cv_search_af_is_double" >&6; }
 ac_res=$ac_cv_search_af_is_double
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
 
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing af_is_double" >&5
-$as_echo_n "checking for library containing af_is_double... " >&6; }
-if ${ac_cv_search_af_is_double+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing af_is_double" >&5
+printf %s "checking for library containing af_is_double... " >&6; }
+if test ${ac_cv_search_af_is_double+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char af_is_double ();
+namespace conftest {
+  extern "C" int af_is_double ();
+}
 int
-main ()
+main (void)
 {
-return af_is_double ();
+return conftest::af_is_double ();
   ;
   return 0;
 }
 _ACEOF
-for ac_lib in '' ; do
+for ac_lib in ''
+do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_cxx_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"
+then :
   ac_cv_search_af_is_double=$ac_res
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext
-  if ${ac_cv_search_af_is_double+:} false; then :
+  if test ${ac_cv_search_af_is_double+y}
+then :
   break
 fi
 done
-if ${ac_cv_search_af_is_double+:} false; then :
+if test ${ac_cv_search_af_is_double+y}
+then :
 
-else
-  ac_cv_search_af_is_double=no
+else case e in #(
+  e) ac_cv_search_af_is_double=no ;;
+esac
 fi
 rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
+LIBS=$ac_func_search_save_LIBS ;;
+esac
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_af_is_double" >&5
-$as_echo "$ac_cv_search_af_is_double" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_af_is_double" >&5
+printf "%s\n" "$ac_cv_search_af_is_double" >&6; }
 ac_res=$ac_cv_search_af_is_double
-if test "$ac_res" != no; then :
+if test "$ac_res" != no
+then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
   found=ok
 fi
@@ -9778,66 +10562,74 @@ fi
 
 fi
 
-
     if test $found = ok ; then
-       $as_echo "#define __PLUMED_HAS_ARRAYFIRE 1" >>confdefs.h
+       printf "%s\n" "#define __PLUMED_HAS_ARRAYFIRE 1" >>confdefs.h
 
        __PLUMED_HAS_ARRAYFIRE=yes
     else
-       { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_ARRAYFIRE" >&5
-$as_echo "$as_me: WARNING: cannot enable __PLUMED_HAS_ARRAYFIRE" >&2;}
+       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_ARRAYFIRE" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable __PLUMED_HAS_ARRAYFIRE" >&2;}
     fi
 
 fi
 
+# metatensor requires libtorch
+if test $metatensor = true ; then
+  libtorch=true;
+fi
+
 #added by luigibonati
 if test $libtorch = true ; then
   # disable as-needed in linking libraries (both static and shared)
 
   save_CXXFLAGS="$CXXFLAGS"
   CXXFLAGS="$CXXFLAGS -Wl,--no-as-needed"
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -Wl,--no-as-needed" >&5
-$as_echo_n "checking whether $CXX accepts -Wl,--no-as-needed... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -Wl,--no-as-needed" >&5
+printf %s "checking whether $CXX accepts -Wl,--no-as-needed... " >&6; }
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"
+then :
 
       cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
-$as_echo "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+if ac_fn_cxx_try_link "$LINENO"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: not linking" >&5
+printf "%s\n" "not linking" >&6; }; CXXFLAGS="$save_CXXFLAGS" ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
-
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }; CXXFLAGS="$save_CXXFLAGS"
+   ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
 
   LDSHARED="$LDSHARED -Wl,--no-as-needed "
 
@@ -9866,12 +10658,11 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
     fi
 
     # check without libraries
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking libtorch_cuda without extra libs" >&5
-$as_echo_n "checking libtorch_cuda without extra libs... " >&6; }
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking libtorch_cuda without extra libs" >&5
+printf %s "checking libtorch_cuda without extra libs... " >&6; }
     cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-    #include <torch/torch.h>
     #include <torch/script.h>
     #include <torch/cuda.h>
     int main() {
@@ -9884,27 +10675,28 @@ $as_echo_n "checking libtorch_cuda without extra libs... " >&6; }
     }
 
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"
+then :
   found=ok
-          { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-
+          { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+       ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
     if test "$found" = "ko" ; then
       if test "$multiple" = "yes" ; then
-        { $as_echo "$as_me:${as_lineno-$LINENO}: checking libtorch_cuda with $all_LIBS" >&5
-$as_echo_n "checking libtorch_cuda with $all_LIBS... " >&6; }
+        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking libtorch_cuda with $all_LIBS" >&5
+printf %s "checking libtorch_cuda with $all_LIBS... " >&6; }
         LIBS="$all_LIBS $LIBS"
         cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-    #include <torch/torch.h>
     #include <torch/script.h>
     #include <torch/cuda.h>
     int main() {
@@ -9917,27 +10709,28 @@ $as_echo_n "checking libtorch_cuda with $all_LIBS... " >&6; }
     }
 
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"
+then :
   found=ok
-              { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-
+              { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+           ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
       else
         for testlib in $testlibs
         do
-          { $as_echo "$as_me:${as_lineno-$LINENO}: checking libtorch_cuda with -l$testlib" >&5
-$as_echo_n "checking libtorch_cuda with -l$testlib... " >&6; }
+          { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking libtorch_cuda with -l$testlib" >&5
+printf %s "checking libtorch_cuda with -l$testlib... " >&6; }
           LIBS="-l$testlib $LIBS"
           cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-    #include <torch/torch.h>
     #include <torch/script.h>
     #include <torch/cuda.h>
     int main() {
@@ -9950,16 +10743,18 @@ $as_echo_n "checking libtorch_cuda with -l$testlib... " >&6; }
     }
 
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"
+then :
   found=ok
-                { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-
+                { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+           ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
           if test $found = ok ; then
             break
@@ -9970,12 +10765,12 @@ rm -f core conftest.err conftest.$ac_objext \
     fi
 
     if test $found = ok ; then
-      $as_echo "#define __PLUMED_HAS_LIBTORCH 1" >>confdefs.h
+      printf "%s\n" "#define __PLUMED_HAS_LIBTORCH 1" >>confdefs.h
 
       __PLUMED_HAS_LIBTORCH=yes
     else
-      { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_LIBTORCH" >&5
-$as_echo "$as_me: WARNING: cannot enable __PLUMED_HAS_LIBTORCH" >&2;}
+      { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_LIBTORCH" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable __PLUMED_HAS_LIBTORCH" >&2;}
       LIBS="$save_LIBS"
     fi
 
@@ -10006,12 +10801,11 @@ $as_echo "$as_me: WARNING: cannot enable __PLUMED_HAS_LIBTORCH" >&2;}
     fi
 
     # check without libraries
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking libtorch_cpu without extra libs" >&5
-$as_echo_n "checking libtorch_cpu without extra libs... " >&6; }
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking libtorch_cpu without extra libs" >&5
+printf %s "checking libtorch_cpu without extra libs... " >&6; }
     cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-    #include <torch/torch.h>
     #include <torch/script.h>
     int main() {
       torch::Tensor tensor = torch::rand({2, 3});
@@ -10020,27 +10814,28 @@ $as_echo_n "checking libtorch_cpu without extra libs... " >&6; }
     }
 
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"
+then :
   found=ok
-          { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-
+          { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+       ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
     if test "$found" = "ko" ; then
       if test "$multiple" = "yes" ; then
-        { $as_echo "$as_me:${as_lineno-$LINENO}: checking libtorch_cpu with $all_LIBS" >&5
-$as_echo_n "checking libtorch_cpu with $all_LIBS... " >&6; }
+        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking libtorch_cpu with $all_LIBS" >&5
+printf %s "checking libtorch_cpu with $all_LIBS... " >&6; }
         LIBS="$all_LIBS $LIBS"
         cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-    #include <torch/torch.h>
     #include <torch/script.h>
     int main() {
       torch::Tensor tensor = torch::rand({2, 3});
@@ -10049,27 +10844,28 @@ $as_echo_n "checking libtorch_cpu with $all_LIBS... " >&6; }
     }
 
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"
+then :
   found=ok
-              { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-
+              { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+           ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
       else
         for testlib in $testlibs
         do
-          { $as_echo "$as_me:${as_lineno-$LINENO}: checking libtorch_cpu with -l$testlib" >&5
-$as_echo_n "checking libtorch_cpu with -l$testlib... " >&6; }
+          { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking libtorch_cpu with -l$testlib" >&5
+printf %s "checking libtorch_cpu with -l$testlib... " >&6; }
           LIBS="-l$testlib $LIBS"
           cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-    #include <torch/torch.h>
     #include <torch/script.h>
     int main() {
       torch::Tensor tensor = torch::rand({2, 3});
@@ -10078,16 +10874,18 @@ $as_echo_n "checking libtorch_cpu with -l$testlib... " >&6; }
     }
 
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"
+then :
   found=ok
-                { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-
+                { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+           ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
           if test $found = ok ; then
             break
@@ -10098,23 +10896,151 @@ rm -f core conftest.err conftest.$ac_objext \
     fi
 
     if test $found = ok ; then
-      $as_echo "#define __PLUMED_HAS_LIBTORCH 1" >>confdefs.h
+      printf "%s\n" "#define __PLUMED_HAS_LIBTORCH 1" >>confdefs.h
 
       __PLUMED_HAS_LIBTORCH=yes
     else
-      { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_LIBTORCH" >&5
-$as_echo "$as_me: WARNING: cannot enable __PLUMED_HAS_LIBTORCH" >&2;}
+      { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_LIBTORCH" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable __PLUMED_HAS_LIBTORCH" >&2;}
       LIBS="$save_LIBS"
     fi
 
   fi
 fi
 
+if test $metatensor = true ; then
+  # find metatensor and metatensor_torch
+
+    found=ko
+    __PLUMED_HAS_METATENSOR=no
+    if test "${libsearch}" = true ; then
+      testlibs="metatensor metatensor_torch"
+    else
+      testlibs=""
+    fi
+    save_LIBS="$LIBS"
+
+    # check if multiple libraries are required simultaneously
+    multiple="no"
+    if test "true" = "true"; then
+      multiple="yes"
+      all_LIBS=""
+      for testlib in $testlibs;
+      do
+        all_LIBS="$all_LIBS -l$testlib"
+      done
+      testlibs=" " # to check only without libraries, and later with all together
+    fi
+
+    # check without libraries
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking metatensor without extra libs" >&5
+printf %s "checking metatensor without extra libs... " >&6; }
+    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+    #include <metatensor/torch.hpp>
+    int main() {
+      metatensor_torch::version();
+      return 0;
+    }
+
+_ACEOF
+if ac_fn_cxx_try_link "$LINENO"
+then :
+  found=ok
+          { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+       ;;
+esac
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
+    conftest$ac_exeext conftest.$ac_ext
+
+    if test "$found" = "ko" ; then
+      if test "$multiple" = "yes" ; then
+        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking metatensor with $all_LIBS" >&5
+printf %s "checking metatensor with $all_LIBS... " >&6; }
+        LIBS="$all_LIBS $LIBS"
+        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+    #include <metatensor/torch.hpp>
+    int main() {
+      metatensor_torch::version();
+      return 0;
+    }
+
+_ACEOF
+if ac_fn_cxx_try_link "$LINENO"
+then :
+  found=ok
+              { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+           ;;
+esac
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
+    conftest$ac_exeext conftest.$ac_ext
+      else
+        for testlib in $testlibs
+        do
+          { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking metatensor with -l$testlib" >&5
+printf %s "checking metatensor with -l$testlib... " >&6; }
+          LIBS="-l$testlib $LIBS"
+          cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+    #include <metatensor/torch.hpp>
+    int main() {
+      metatensor_torch::version();
+      return 0;
+    }
+
+_ACEOF
+if ac_fn_cxx_try_link "$LINENO"
+then :
+  found=ok
+                { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+           ;;
+esac
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
+    conftest$ac_exeext conftest.$ac_ext
+          if test $found = ok ; then
+            break
+          fi
+          LIBS="$save_LIBS"
+        done
+      fi
+    fi
+
+    if test $found = ok ; then
+      printf "%s\n" "#define __PLUMED_HAS_METATENSOR 1" >>confdefs.h
+
+      __PLUMED_HAS_METATENSOR=yes
+    else
+      { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cannot enable __PLUMED_HAS_METATENSOR" >&5
+printf "%s\n" "$as_me: WARNING: cannot enable __PLUMED_HAS_METATENSOR" >&2;}
+      LIBS="$save_LIBS"
+    fi
+
+fi
+
 # in non-debug mode, add -DNDEBUG
 if test "$debug" = false ; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: Release mode, adding -DNDEBUG" >&5
-$as_echo "$as_me: Release mode, adding -DNDEBUG" >&6;}
-  $as_echo "#define NDEBUG 1" >>confdefs.h
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Release mode, adding -DNDEBUG" >&5
+printf "%s\n" "$as_me: Release mode, adding -DNDEBUG" >&6;}
+  printf "%s\n" "#define NDEBUG 1" >>confdefs.h
 
 fi
 
@@ -10123,16 +11049,16 @@ fi
 # also take note that we are using this to relax `make nmcheck`
 use_debug_glibcxx=no
 if test "$debug_glibcxx" = true ; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: Check boundaries, adding -D_GLIBCXX_DEBUG" >&5
-$as_echo "$as_me: Check boundaries, adding -D_GLIBCXX_DEBUG" >&6;}
-  $as_echo "#define _GLIBCXX_DEBUG 1" >>confdefs.h
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Check boundaries, adding -D_GLIBCXX_DEBUG" >&5
+printf "%s\n" "$as_me: Check boundaries, adding -D_GLIBCXX_DEBUG" >&6;}
+  printf "%s\n" "#define _GLIBCXX_DEBUG 1" >>confdefs.h
 
   use_debug_glibcxx=yes
 fi
 
 # this is necessary in many MPI implementations
 # I leave it by default, since it seems harmless
-$as_echo "#define _REENTRANT 1" >>confdefs.h
+printf "%s\n" "#define _REENTRANT 1" >>confdefs.h
 
 
 #### Options for dynamic library to work properly ####
@@ -10147,112 +11073,116 @@ $as_echo "#define _REENTRANT 1" >>confdefs.h
 if test "$shared" = true ; then
   case `(uname)` in
   (Darwin)
-    { $as_echo "$as_me:${as_lineno-$LINENO}: *** Special settings for dynamic libraries on OSX ***" >&5
-$as_echo "$as_me: *** Special settings for dynamic libraries on OSX ***" >&6;}
-    { $as_echo "$as_me:${as_lineno-$LINENO}: Dynamic library extension is 'dylib'" >&5
-$as_echo "$as_me: Dynamic library extension is 'dylib'" >&6;}
-    { $as_echo "$as_me:${as_lineno-$LINENO}: LDSHARED needs special flags" >&5
-$as_echo "$as_me: LDSHARED needs special flags" >&6;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: *** Special settings for dynamic libraries on OSX ***" >&5
+printf "%s\n" "$as_me: *** Special settings for dynamic libraries on OSX ***" >&6;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Dynamic library extension is 'dylib'" >&5
+printf "%s\n" "$as_me: Dynamic library extension is 'dylib'" >&6;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: LDSHARED needs special flags" >&5
+printf "%s\n" "$as_me: LDSHARED needs special flags" >&6;}
     SOEXT=dylib
     LDSHARED="$LDSHARED -dynamiclib -Wl,-headerpad_max_install_names"
     if test "$rpath" = true ; then
-      { $as_echo "$as_me:${as_lineno-$LINENO}: Switching off rpath on OSX" >&5
-$as_echo "$as_me: Switching off rpath on OSX" >&6;}
+      { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Switching off rpath on OSX" >&5
+printf "%s\n" "$as_me: Switching off rpath on OSX" >&6;}
       rpath=false
     fi
   ;;
   (Linux)
-    { $as_echo "$as_me:${as_lineno-$LINENO}: *** Special settings for dynamic libraries on Linux ***" >&5
-$as_echo "$as_me: *** Special settings for dynamic libraries on Linux ***" >&6;}
-    { $as_echo "$as_me:${as_lineno-$LINENO}: Dynamic library extension is 'so'" >&5
-$as_echo "$as_me: Dynamic library extension is 'so'" >&6;}
-    { $as_echo "$as_me:${as_lineno-$LINENO}: LDSHARED and LDFLAGS need special flags" >&5
-$as_echo "$as_me: LDSHARED and LDFLAGS need special flags" >&6;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: *** Special settings for dynamic libraries on Linux ***" >&5
+printf "%s\n" "$as_me: *** Special settings for dynamic libraries on Linux ***" >&6;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Dynamic library extension is 'so'" >&5
+printf "%s\n" "$as_me: Dynamic library extension is 'so'" >&6;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: LDSHARED and LDFLAGS need special flags" >&5
+printf "%s\n" "$as_me: LDSHARED and LDFLAGS need special flags" >&6;}
     SOEXT=so
     LDSHARED="$LDSHARED -shared"
 
   save_LDFLAGS="$LDFLAGS"
   LDFLAGS="$LDFLAGS -rdynamic"
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether LDFLAGS can contain -rdynamic" >&5
-$as_echo_n "checking whether LDFLAGS can contain -rdynamic... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether LDFLAGS can contain -rdynamic" >&5
+printf %s "checking whether LDFLAGS can contain -rdynamic... " >&6; }
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }; LDFLAGS="$save_LDFLAGS"
+if ac_fn_cxx_try_link "$LINENO"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }; LDFLAGS="$save_LDFLAGS" ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
     if test "$bsymbolic" = true ; then
 
   save_LDFLAGS="$LDFLAGS"
   LDFLAGS="$LDFLAGS -Wl,-Bsymbolic"
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether LDFLAGS can contain -Wl,-Bsymbolic" >&5
-$as_echo_n "checking whether LDFLAGS can contain -Wl,-Bsymbolic... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether LDFLAGS can contain -Wl,-Bsymbolic" >&5
+printf %s "checking whether LDFLAGS can contain -Wl,-Bsymbolic... " >&6; }
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
-main ()
+main (void)
 {
 
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_cxx_try_link "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }; LDFLAGS="$save_LDFLAGS"
+if ac_fn_cxx_try_link "$LINENO"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }; LDFLAGS="$save_LDFLAGS" ;;
+esac
 fi
-rm -f core conftest.err conftest.$ac_objext \
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
     fi
   ;;
   (*)
-    { $as_echo "$as_me:${as_lineno-$LINENO}: *** Dynamic library only enabled on OSX and Linux ***" >&5
-$as_echo "$as_me: *** Dynamic library only enabled on OSX and Linux ***" >&6;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: *** Dynamic library only enabled on OSX and Linux ***" >&5
+printf "%s\n" "$as_me: *** Dynamic library only enabled on OSX and Linux ***" >&6;}
   esac
 fi
 
 # check linking of runtime library
 if test -n "$SOEXT"
 then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: Using LDSHARED='$LDSHARED'" >&5
-$as_echo "$as_me: Using LDSHARED='$LDSHARED'" >&6;}
-  { $as_echo "$as_me:${as_lineno-$LINENO}: Using LDFLAGS='$LDFLAGS'" >&5
-$as_echo "$as_me: Using LDFLAGS='$LDFLAGS'" >&6;}
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether LDSHARED can create dynamic libraries" >&5
-$as_echo_n "checking whether LDSHARED can create dynamic libraries... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Using LDSHARED='$LDSHARED'" >&5
+printf "%s\n" "$as_me: Using LDSHARED='$LDSHARED'" >&6;}
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Using LDFLAGS='$LDFLAGS'" >&5
+printf "%s\n" "$as_me: Using LDFLAGS='$LDFLAGS'" >&6;}
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether LDSHARED can create dynamic libraries" >&5
+printf %s "checking whether LDSHARED can create dynamic libraries... " >&6; }
   rm -f conftest.*
   echo "void f(void){ return;}" > conftest.cpp
   $CXX $CXXFLAGS $CPPFLAGS -c conftest.cpp 1>/dev/null 2>/dev/null
   $LDSHARED $LDFLAGS conftest.o -o conftest.$SOEXT 1>/dev/null 2>/dev/null
   if test -f conftest.$SOEXT
   then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: dynamic library will be disabled" >&5
-$as_echo "$as_me: WARNING: dynamic library will be disabled" >&2;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: dynamic library will be disabled" >&5
+printf "%s\n" "$as_me: WARNING: dynamic library will be disabled" >&2;}
     SOEXT=
   fi
   if test -n "$SOEXT" && test "$rpath" = true ; then
@@ -10260,38 +11190,44 @@ $as_echo "$as_me: WARNING: dynamic library will be disabled" >&2;}
     readelf=""
     # Extract the first word of "readelf", so it can be a program name with args.
 set dummy readelf; ac_word=$2
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
-$as_echo_n "checking for $ac_word... " >&6; }
-if ${ac_cv_prog_readelf+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  if test -n "$readelf"; then
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+printf %s "checking for $ac_word... " >&6; }
+if test ${ac_cv_prog_readelf+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) if test -n "$readelf"; then
   ac_cv_prog_readelf="$readelf" # Let the user override the test.
 else
 as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
 for as_dir in $PATH
 do
   IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
+  case $as_dir in #(((
+    '') as_dir=./ ;;
+    */) ;;
+    *) as_dir=$as_dir/ ;;
+  esac
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+  if as_fn_executable_p "$as_dir$ac_word$ac_exec_ext"; then
     ac_cv_prog_readelf="found"
-    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    printf "%s\n" "$as_me:${as_lineno-$LINENO}: found $as_dir$ac_word$ac_exec_ext" >&5
     break 2
   fi
 done
   done
 IFS=$as_save_IFS
 
-fi
+fi ;;
+esac
 fi
 readelf=$ac_cv_prog_readelf
 if test -n "$readelf"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $readelf" >&5
-$as_echo "$readelf" >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $readelf" >&5
+printf "%s\n" "$readelf" >&6; }
 else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
 fi
 
 
@@ -10301,20 +11237,20 @@ fi
       if readelf -d conftest.$SOEXT | grep RPATH | grep -q /some/random/dir ; then
         LD_MAIN_RUNPATH="-Wl,-R -Wl,\"$libdir:$LIBRARY_PATH\""
         LDSHARED="$LDSHARED $LD_MAIN_RUNPATH"
-        { $as_echo "$as_me:${as_lineno-$LINENO}: Enabling RPATH" >&5
-$as_echo "$as_me: Enabling RPATH" >&6;}
+        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Enabling RPATH" >&5
+printf "%s\n" "$as_me: Enabling RPATH" >&6;}
       elif readelf -d conftest.$SOEXT | grep RUNPATH | grep -q /some/random/dir ; then
         LD_MAIN_RUNPATH="-Wl,-R -Wl,\"$libdir:$LIBRARY_PATH\""
         LDSHARED="$LDSHARED $LD_MAIN_RUNPATH"
-        { $as_echo "$as_me:${as_lineno-$LINENO}: Enabling RUNPATH" >&5
-$as_echo "$as_me: Enabling RUNPATH" >&6;}
+        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Enabling RUNPATH" >&5
+printf "%s\n" "$as_me: Enabling RUNPATH" >&6;}
       else
-        { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: -R option seems not working, disabling rpath" >&5
-$as_echo "$as_me: WARNING: -R option seems not working, disabling rpath" >&2;}
+        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: -R option seems not working, disabling rpath" >&5
+printf "%s\n" "$as_me: WARNING: -R option seems not working, disabling rpath" >&2;}
       fi
     else
-      { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: readelf not available, no way to set rpath" >&5
-$as_echo "$as_me: WARNING: readelf not available, no way to set rpath" >&2;}
+      { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: readelf not available, no way to set rpath" >&5
+printf "%s\n" "$as_me: WARNING: readelf not available, no way to set rpath" >&2;}
     fi
   fi
   rm -f conftest.*
@@ -10331,38 +11267,44 @@ make_doc=yes
 ### Look for doxygen
 # Extract the first word of "doxygen", so it can be a program name with args.
 set dummy doxygen; ac_word=$2
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
-$as_echo_n "checking for $ac_word... " >&6; }
-if ${ac_cv_prog_doxygen+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  if test -n "$doxygen"; then
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+printf %s "checking for $ac_word... " >&6; }
+if test ${ac_cv_prog_doxygen+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) if test -n "$doxygen"; then
   ac_cv_prog_doxygen="$doxygen" # Let the user override the test.
 else
 as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
 for as_dir in $PATH
 do
   IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
+  case $as_dir in #(((
+    '') as_dir=./ ;;
+    */) ;;
+    *) as_dir=$as_dir/ ;;
+  esac
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+  if as_fn_executable_p "$as_dir$ac_word$ac_exec_ext"; then
     ac_cv_prog_doxygen="found"
-    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    printf "%s\n" "$as_me:${as_lineno-$LINENO}: found $as_dir$ac_word$ac_exec_ext" >&5
     break 2
   fi
 done
   done
 IFS=$as_save_IFS
 
-fi
+fi ;;
+esac
 fi
 doxygen=$ac_cv_prog_doxygen
 if test -n "$doxygen"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $doxygen" >&5
-$as_echo "$doxygen" >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $doxygen" >&5
+printf "%s\n" "$doxygen" >&6; }
 else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
 fi
 
 
@@ -10371,54 +11313,60 @@ then
   doxygen_version=`doxygen --version | awk 'BEGIN{FS="."}{if($1>1 || ($1==1 && $2>=8)) print "ok"}'`
   if test "$doxygen_version" = ok
   then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: Doxygen version is fine" >&5
-$as_echo "$as_me: Doxygen version is fine" >&6;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Doxygen version is fine" >&5
+printf "%s\n" "$as_me: Doxygen version is fine" >&6;}
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Doxygen version is <1.8" >&5
-$as_echo "$as_me: WARNING: Doxygen version is <1.8" >&2;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: Doxygen version is <1.8" >&5
+printf "%s\n" "$as_me: WARNING: Doxygen version is <1.8" >&2;}
     make_doc=no
   fi
   # Extract the first word of "dot", so it can be a program name with args.
 set dummy dot; ac_word=$2
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
-$as_echo_n "checking for $ac_word... " >&6; }
-if ${ac_cv_prog_dot+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  if test -n "$dot"; then
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+printf %s "checking for $ac_word... " >&6; }
+if test ${ac_cv_prog_dot+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) if test -n "$dot"; then
   ac_cv_prog_dot="$dot" # Let the user override the test.
 else
 as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
 for as_dir in $PATH
 do
   IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
+  case $as_dir in #(((
+    '') as_dir=./ ;;
+    */) ;;
+    *) as_dir=$as_dir/ ;;
+  esac
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+  if as_fn_executable_p "$as_dir$ac_word$ac_exec_ext"; then
     ac_cv_prog_dot="found"
-    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    printf "%s\n" "$as_me:${as_lineno-$LINENO}: found $as_dir$ac_word$ac_exec_ext" >&5
     break 2
   fi
 done
   done
 IFS=$as_save_IFS
 
-fi
+fi ;;
+esac
 fi
 dot=$ac_cv_prog_dot
 if test -n "$dot"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $dot" >&5
-$as_echo "$dot" >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $dot" >&5
+printf "%s\n" "$dot" >&6; }
 else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
 fi
 
 
   if test "$dot" != found
   then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: You will not be able to see diagrams in the manual" >&5
-$as_echo "$as_me: WARNING: You will not be able to see diagrams in the manual" >&2;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: You will not be able to see diagrams in the manual" >&5
+printf "%s\n" "$as_me: WARNING: You will not be able to see diagrams in the manual" >&2;}
   fi
 else
   make_doc=no
@@ -10427,36 +11375,37 @@ fi
 
 if test "$make_doc" = yes
 then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: Manuals will be generated" >&5
-$as_echo "$as_me: Manuals will be generated" >&6;}
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Manuals will be generated" >&5
+printf "%s\n" "$as_me: Manuals will be generated" >&6;}
 else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: Manuals will not be generated" >&5
-$as_echo "$as_me: Manuals will not be generated" >&6;}
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Manuals will not be generated" >&5
+printf "%s\n" "$as_me: Manuals will not be generated" >&6;}
 fi
 
 
 make_pdfdoc=""
 if test "$pdfdoc" = true && test "$make_doc" = yes
 then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: A PDF version of the manual will be generated" >&5
-$as_echo "$as_me: A PDF version of the manual will be generated" >&6;}
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: A PDF version of the manual will be generated" >&5
+printf "%s\n" "$as_me: A PDF version of the manual will be generated" >&6;}
   make_pdfdoc=yes
 else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: A PDF version of the manual will not be generated" >&5
-$as_echo "$as_me: A PDF version of the manual will not be generated" >&6;}
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: A PDF version of the manual will not be generated" >&5
+printf "%s\n" "$as_me: A PDF version of the manual will not be generated" >&6;}
   make_pdfdoc=no
 fi
 
 
 program_can_run=""
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether a program can be run on this machine" >&5
-$as_echo_n "checking whether a program can be run on this machine... " >&6; }
-if test "$cross_compiling" = yes; then :
-   program_can_run=no ; { $as_echo "$as_me:${as_lineno-$LINENO}: result: no (cross compiling)" >&5
-$as_echo "no (cross compiling)" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether a program can be run on this machine" >&5
+printf %s "checking whether a program can be run on this machine... " >&6; }
+if test "$cross_compiling" = yes
+then :
+   program_can_run=no ; { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no (cross compiling)" >&5
+printf "%s\n" "no (cross compiling)" >&6; }
 
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+else case e in #(
+  e) cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 #ifdef __PLUMED_HAS_MPI
@@ -10476,29 +11425,33 @@ int main(int argc,char*argv[]){
 }
 
 _ACEOF
-if ac_fn_cxx_try_run "$LINENO"; then :
-   program_can_run=yes ; { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-   program_can_run=no ; { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
+if ac_fn_cxx_try_run "$LINENO"
+then :
+   program_can_run=yes ; { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e)  program_can_run=no ; { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }  ;;
+esac
 fi
 rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
-  conftest.$ac_objext conftest.beam conftest.$ac_ext
+  conftest.$ac_objext conftest.beam conftest.$ac_ext ;;
+esac
 fi
 
 
 if test $mpi_found = ok ; then
 
 program_can_run_mpi=""
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether a program compiled with mpi can be run on this machine" >&5
-$as_echo_n "checking whether a program compiled with mpi can be run on this machine... " >&6; }
-if test "$cross_compiling" = yes; then :
-   program_can_run_mpi=no ; { $as_echo "$as_me:${as_lineno-$LINENO}: result: no (cross compiling)" >&5
-$as_echo "no (cross compiling)" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether a program compiled with mpi can be run on this machine" >&5
+printf %s "checking whether a program compiled with mpi can be run on this machine... " >&6; }
+if test "$cross_compiling" = yes
+then :
+   program_can_run_mpi=no ; { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no (cross compiling)" >&5
+printf "%s\n" "no (cross compiling)" >&6; }
 
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+else case e in #(
+  e) cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 #ifdef __PLUMED_HAS_MPI
@@ -10514,26 +11467,29 @@ int main(int argc,char*argv[]){
 }
 
 _ACEOF
-if ac_fn_cxx_try_run "$LINENO"; then :
-   program_can_run_mpi=yes ; { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
-   program_can_run_mpi=no ; { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
+if ac_fn_cxx_try_run "$LINENO"
+then :
+   program_can_run_mpi=yes ; { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+else case e in #(
+  e)  program_can_run_mpi=no ; { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }  ;;
+esac
 fi
 rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
-  conftest.$ac_objext conftest.beam conftest.$ac_ext
+  conftest.$ac_objext conftest.beam conftest.$ac_ext ;;
+esac
 fi
 
 fi
 
 if test $mpi_found = ok ; then
   if test -n "$MPIEXEC" ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: Regtest suite will use $MPIEXEC command to run MPI tests" >&5
-$as_echo "$as_me: Regtest suite will use $MPIEXEC command to run MPI tests" >&6;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Regtest suite will use $MPIEXEC command to run MPI tests" >&5
+printf "%s\n" "$as_me: Regtest suite will use $MPIEXEC command to run MPI tests" >&6;}
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: Regtest suite will use env var PLUMED_MPIRUN to run MPI tests (default: mpirun)" >&5
-$as_echo "$as_me: Regtest suite will use env var PLUMED_MPIRUN to run MPI tests (default: mpirun)" >&6;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Regtest suite will use env var PLUMED_MPIRUN to run MPI tests (default: mpirun)" >&5
+printf "%s\n" "$as_me: Regtest suite will use env var PLUMED_MPIRUN to run MPI tests (default: mpirun)" >&6;}
   fi
 fi
 
@@ -10546,22 +11502,22 @@ fi
 
 if test "$absolute_soname" = true ; then
   if test "$SOEXT" = "dylib" ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: --enable-absolute-soname has no effect on OSX" >&5
-$as_echo "$as_me: WARNING: --enable-absolute-soname has no effect on OSX" >&2;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: --enable-absolute-soname has no effect on OSX" >&5
+printf "%s\n" "$as_me: WARNING: --enable-absolute-soname has no effect on OSX" >&2;}
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: enabling absolute soname. Full path will be hardcoded in plumed library soname" >&5
-$as_echo "$as_me: enabling absolute soname. Full path will be hardcoded in plumed library soname" >&6;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: enabling absolute soname. Full path will be hardcoded in plumed library soname" >&5
+printf "%s\n" "$as_me: enabling absolute soname. Full path will be hardcoded in plumed library soname" >&6;}
     use_absolute_soname=yes
   fi
 fi
 
 if test "$absolute_install_name" = false ; then
   if test "$SOEXT" = "so" ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: --disable-absolute-install-name has no effect on Linux" >&5
-$as_echo "$as_me: WARNING: --disable-absolute-install-name has no effect on Linux" >&2;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: --disable-absolute-install-name has no effect on Linux" >&5
+printf "%s\n" "$as_me: WARNING: --disable-absolute-install-name has no effect on Linux" >&2;}
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: enabling relative install_name. You will have to set DYLD_LIBRARY_PATH yor plumed libraries to be found at runtime" >&5
-$as_echo "$as_me: enabling relative install_name. You will have to set DYLD_LIBRARY_PATH yor plumed libraries to be found at runtime" >&6;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: enabling relative install_name. You will have to set DYLD_LIBRARY_PATH yor plumed libraries to be found at runtime" >&5
+printf "%s\n" "$as_me: enabling relative install_name. You will have to set DYLD_LIBRARY_PATH yor plumed libraries to be found at runtime" >&6;}
     use_absolute_soname=no
   fi
 fi
@@ -10578,17 +11534,17 @@ else
 fi
 
 #### This further tests are required to allow linking with non c++ compiler
-{ $as_echo "$as_me:${as_lineno-$LINENO}: PLUMED seems to be configured properly!" >&5
-$as_echo "$as_me: PLUMED seems to be configured properly!" >&6;}
-{ $as_echo "$as_me:${as_lineno-$LINENO}: **************************" >&5
-$as_echo "$as_me: **************************" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: PLUMED seems to be configured properly!" >&5
+printf "%s\n" "$as_me: PLUMED seems to be configured properly!" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: **************************" >&5
+printf "%s\n" "$as_me: **************************" >&6;}
 
 LD_RO=
 if test "$ld_r" = true ; then
 for test_LD_RO in "$($CXX --print-prog-name=ld) -r -o" "$CXX -Wl,-r -o" "ld -r -o"
 do
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether C++ objects can be grouped with $test_LD_RO" >&5
-$as_echo_n "checking whether C++ objects can be grouped with $test_LD_RO... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether C++ objects can be grouped with $test_LD_RO" >&5
+printf %s "checking whether C++ objects can be grouped with $test_LD_RO... " >&6; }
 
   rm -f conftest*
 
@@ -10614,13 +11570,13 @@ EOF
 
   if test -f conftest.exe
   then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
     LD_RO="$test_LD_RO"
     break
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
   fi
 done
 
@@ -10631,8 +11587,8 @@ AR_CR=
 if test "$ar_cr" = true ; then
 for test_AR_CR in "$($CXX --print-prog-name=ar) cr" "ar cr"
 do
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether static libraries can be created with $test_AR_CR" >&5
-$as_echo_n "checking whether static libraries can be created with $test_AR_CR... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether static libraries can be created with $test_AR_CR" >&5
+printf %s "checking whether static libraries can be created with $test_AR_CR... " >&6; }
 
   rm -f conftest*
 
@@ -10658,13 +11614,13 @@ EOF
 
   if test -f conftest.exe
   then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
     AR_CR="$test_AR_CR"
     break
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
   fi
 done
 
@@ -10675,15 +11631,15 @@ make_static_archive=no
 
 if test "${static_archive}" = true ; then
   if test -z "$LD_RO" || test -z "$AR_CR" ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: no way to create a static archive if ld -ro or ar cr do not work" >&5
-$as_echo "$as_me: WARNING: no way to create a static archive if ld -ro or ar cr do not work" >&2;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: no way to create a static archive if ld -ro or ar cr do not work" >&5
+printf "%s\n" "$as_me: WARNING: no way to create a static archive if ld -ro or ar cr do not work" >&2;}
     static_archive=false
   fi
 fi
 
 if test "${static_archive}" = true ; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether static-object constructors can be linked from a static archive" >&5
-$as_echo_n "checking whether static-object constructors can be linked from a static archive... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether static-object constructors can be linked from a static archive" >&5
+printf %s "checking whether static-object constructors can be linked from a static archive... " >&6; }
 
   magic_token=c1bc476d093a3a5c67b4530e6c54c633593fe9aa
   rm -f conftest-*
@@ -10715,21 +11671,21 @@ EOF
 #
   $CXX $CXXFLAGS -o conftest.exe conftest-main.o conftest-both.a 1> /dev/null 2> /dev/null
   if grep -q $magic_token ./conftest.exe ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
     make_static_archive=yes
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
   fi
 fi
 
 if test "${static_patch}" = true ; then
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: I will now check if C++ objects can be linked by C/Fortran compilers" >&5
-$as_echo "$as_me: I will now check if C++ objects can be linked by C/Fortran compilers" >&6;}
-{ $as_echo "$as_me:${as_lineno-$LINENO}: This is relevant if you want to use plumed patch --static on a non-C++ code" >&5
-$as_echo "$as_me: This is relevant if you want to use plumed patch --static on a non-C++ code" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: I will now check if C++ objects can be linked by C/Fortran compilers" >&5
+printf "%s\n" "$as_me: I will now check if C++ objects can be linked by C/Fortran compilers" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: This is relevant if you want to use plumed patch --static on a non-C++ code" >&5
+printf "%s\n" "$as_me: This is relevant if you want to use plumed patch --static on a non-C++ code" >&6;}
 
 for compiler in CC FC
 do
@@ -10773,37 +11729,37 @@ EOF
     for testlib in "" $testlibs ; do
       comment=
       test -n "$testlib" && comment=" with library $testlib"
-      { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $name can link a C++ object$comment" >&5
-$as_echo_n "checking whether $name can link a C++ object$comment... " >&6; }
+      { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $name can link a C++ object$comment" >&5
+printf %s "checking whether $name can link a C++ object$comment... " >&6; }
       $compexe conftest.o conftest-main.o $LDFLAGS $testlib $LIBS -o conftest.exe 1>/dev/null 2>/dev/null
       if test -f conftest.exe
       then
         found=yes
-        { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
+        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
         LIBS="$testlib $LIBS"
         break
       else
-        { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
+        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
       fi
     done
     if test -z "$found" ; then
-      { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: You might have problems linking $name programs." >&5
-$as_echo "$as_me: WARNING: You might have problems linking $name programs." >&2;}
-      { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Please add c++ library to LIBS" >&5
-$as_echo "$as_me: WARNING: Please add c++ library to LIBS" >&2;}
+      { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: You might have problems linking $name programs." >&5
+printf "%s\n" "$as_me: WARNING: You might have problems linking $name programs." >&2;}
+      { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: Please add c++ library to LIBS" >&5
+printf "%s\n" "$as_me: WARNING: Please add c++ library to LIBS" >&2;}
     fi
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: $compiler compiler not configured" >&5
-$as_echo "$as_me: $compiler compiler not configured" >&6;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: $compiler compiler not configured" >&5
+printf "%s\n" "$as_me: $compiler compiler not configured" >&6;}
   fi
   rm -f conftest.* conftest-main.*
 done
 
 else
-{ $as_echo "$as_me:${as_lineno-$LINENO}: Static patching is disabled, thus tests required for static patching will be skipped" >&5
-$as_echo "$as_me: Static patching is disabled, thus tests required for static patching will be skipped" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: Static patching is disabled, thus tests required for static patching will be skipped" >&5
+printf "%s\n" "$as_me: Static patching is disabled, thus tests required for static patching will be skipped" >&6;}
 fi
 
 if test "$prefix" = NONE
@@ -10817,12 +11773,13 @@ for ac_prog in pkg-config
 do
   # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
-$as_echo_n "checking for $ac_word... " >&6; }
-if ${ac_cv_path_pkgconfig_bin+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  case $pkgconfig_bin in
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+printf %s "checking for $ac_word... " >&6; }
+if test ${ac_cv_path_pkgconfig_bin+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) case $pkgconfig_bin in
   [\\/]* | ?:[\\/]*)
   ac_cv_path_pkgconfig_bin="$pkgconfig_bin" # Let the user override the test with a path.
   ;;
@@ -10831,11 +11788,15 @@ else
 for as_dir in $PATH
 do
   IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
+  case $as_dir in #(((
+    '') as_dir=./ ;;
+    */) ;;
+    *) as_dir=$as_dir/ ;;
+  esac
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
-    ac_cv_path_pkgconfig_bin="$as_dir/$ac_word$ac_exec_ext"
-    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+  if as_fn_executable_p "$as_dir$ac_word$ac_exec_ext"; then
+    ac_cv_path_pkgconfig_bin="$as_dir$ac_word$ac_exec_ext"
+    printf "%s\n" "$as_me:${as_lineno-$LINENO}: found $as_dir$ac_word$ac_exec_ext" >&5
     break 2
   fi
 done
@@ -10843,15 +11804,16 @@ done
 IFS=$as_save_IFS
 
   ;;
+esac ;;
 esac
 fi
 pkgconfig_bin=$ac_cv_path_pkgconfig_bin
 if test -n "$pkgconfig_bin"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $pkgconfig_bin" >&5
-$as_echo "$pkgconfig_bin" >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $pkgconfig_bin" >&5
+printf "%s\n" "$pkgconfig_bin" >&6; }
 else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
 fi
 
 
@@ -10862,25 +11824,25 @@ done
 if test -z "$BASH_COMPLETION_DIR" && test -n "$pkgconfig_bin"; then
   if test "$prefix" = "$(pkg-config --variable=prefix bash-completion 2>/dev/null)"
   then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: bash-completion is installed on the same prefix where plumed will be installed" >&5
-$as_echo "$as_me: bash-completion is installed on the same prefix where plumed will be installed" >&6;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: bash-completion is installed on the same prefix where plumed will be installed" >&5
+printf "%s\n" "$as_me: bash-completion is installed on the same prefix where plumed will be installed" >&6;}
     if pkg-config --variable=completionsdir bash-completion 2>/dev/null >/dev/null ; then
       BASH_COMPLETION_DIR="$(pkg-config --variable=completionsdir  bash-completion 2>/dev/null)"
     fi
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: bash-completion is not installed or it is installed on a different prefix" >&5
-$as_echo "$as_me: bash-completion is not installed or it is installed on a different prefix" >&6;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: bash-completion is not installed or it is installed on a different prefix" >&5
+printf "%s\n" "$as_me: bash-completion is not installed or it is installed on a different prefix" >&6;}
     pkgconfig_bin=""
   fi
 fi
 
 if test -n "$BASH_COMPLETION_DIR"
 then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: bash completion for plumed will be installed in $BASH_COMPLETION_DIR" >&5
-$as_echo "$as_me: bash completion for plumed will be installed in $BASH_COMPLETION_DIR" >&6;}
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: bash completion for plumed will be installed in $BASH_COMPLETION_DIR" >&5
+printf "%s\n" "$as_me: bash completion for plumed will be installed in $BASH_COMPLETION_DIR" >&6;}
 else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: bash completion for plumed will not be installed" >&5
-$as_echo "$as_me: bash completion for plumed will not be installed" >&6;}
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: bash completion for plumed will not be installed" >&5
+printf "%s\n" "$as_me: bash completion for plumed will not be installed" >&6;}
 fi
 
 
@@ -10891,9 +11853,9 @@ test "$program_prefix" != NONE &&
 test "$program_suffix" != NONE &&
   program_transform_name="s&\$&$program_suffix&;$program_transform_name"
 # Double any \ or $.
-# By default was `s,x,x', remove it if useless.
+# By default was 's,x,x', remove it if useless.
 ac_script='s/[\\$]/&&/g;s/;s,x,x,$//'
-program_transform_name=`$as_echo "$program_transform_name" | sed "$ac_script"`
+program_transform_name=`printf "%s\n" "$program_transform_name" | sed "$ac_script"`
 
 
 
@@ -10901,13 +11863,9 @@ program_transform_name=`$as_echo "$program_transform_name" | sed "$ac_script"`
 program_transform_name_sh=$(echo "${program_transform_name}" | sed 's:\$\$:$:g')
 program_name=$(echo plumed | sed "$program_transform_name_sh")
 
-cat >>confdefs.h <<_ACEOF
-#define __PLUMED_PROGRAM_NAME "$program_name"
-_ACEOF
+printf "%s\n" "#define __PLUMED_PROGRAM_NAME \"$program_name\"" >>confdefs.h
 
-cat >>confdefs.h <<_ACEOF
-#define __PLUMED_SOEXT "$SOEXT"
-_ACEOF
+printf "%s\n" "#define __PLUMED_SOEXT \"$SOEXT\"" >>confdefs.h
 
 
 if test "$(echo "$program_name" | tr 'A-Z' 'a-z')" != "$(echo "$program_name" | tr 'A-Z' 'a-z' | sed 's/wrapper$//')" ; then
@@ -10923,79 +11881,79 @@ if test "$(echo "$program_name" | tr 'A-Z' 'a-z')" != "$(echo "$program_name" |
   as_fn_error $? "$program_name is not a valid program name (should not terminate with -config)" "$LINENO" 5
 fi
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: **** PLUMED will be installed using the following paths:" >&5
-$as_echo "$as_me: **** PLUMED will be installed using the following paths:" >&6;}
-{ $as_echo "$as_me:${as_lineno-$LINENO}: **** prefix: $prefix" >&5
-$as_echo "$as_me: **** prefix: $prefix" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: **** PLUMED will be installed using the following paths:" >&5
+printf "%s\n" "$as_me: **** PLUMED will be installed using the following paths:" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: **** prefix: $prefix" >&5
+printf "%s\n" "$as_me: **** prefix: $prefix" >&6;}
 if test "$exec_prefix" = NONE ; then
   exec_prefix_='${prefix}'
 else
   exec_prefix_="${exec_prefix}"
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: **** exec_prefix: $exec_prefix_" >&5
-$as_echo "$as_me: **** exec_prefix: $exec_prefix_" >&6;}
-{ $as_echo "$as_me:${as_lineno-$LINENO}: **** bindir: $bindir" >&5
-$as_echo "$as_me: **** bindir: $bindir" >&6;}
-{ $as_echo "$as_me:${as_lineno-$LINENO}: **** libdir: $libdir" >&5
-$as_echo "$as_me: **** libdir: $libdir" >&6;}
-{ $as_echo "$as_me:${as_lineno-$LINENO}: **** includedir: $includedir" >&5
-$as_echo "$as_me: **** includedir: $includedir" >&6;}
-{ $as_echo "$as_me:${as_lineno-$LINENO}: **** datarootdir: $datarootdir" >&5
-$as_echo "$as_me: **** datarootdir: $datarootdir" >&6;}
-{ $as_echo "$as_me:${as_lineno-$LINENO}: **** datadir: $datadir" >&5
-$as_echo "$as_me: **** datadir: $datadir" >&6;}
-{ $as_echo "$as_me:${as_lineno-$LINENO}: **** docdir: ${datarootdir}/doc/$program_name" >&5
-$as_echo "$as_me: **** docdir: ${datarootdir}/doc/$program_name" >&6;}
-{ $as_echo "$as_me:${as_lineno-$LINENO}: **** htmldir: $htmldir" >&5
-$as_echo "$as_me: **** htmldir: $htmldir" >&6;}
-{ $as_echo "$as_me:${as_lineno-$LINENO}: **** Executable will be named $program_name" >&5
-$as_echo "$as_me: **** Executable will be named $program_name" >&6;}
-{ $as_echo "$as_me:${as_lineno-$LINENO}: **** As of PLUMED 2.5, you cannot change paths anymore during \"make install\"" >&5
-$as_echo "$as_me: **** As of PLUMED 2.5, you cannot change paths anymore during \"make install\"" >&6;}
-{ $as_echo "$as_me:${as_lineno-$LINENO}: **** Please configure and make clean to change the prefix" >&5
-$as_echo "$as_me: **** Please configure and make clean to change the prefix" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: **** exec_prefix: $exec_prefix_" >&5
+printf "%s\n" "$as_me: **** exec_prefix: $exec_prefix_" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: **** bindir: $bindir" >&5
+printf "%s\n" "$as_me: **** bindir: $bindir" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: **** libdir: $libdir" >&5
+printf "%s\n" "$as_me: **** libdir: $libdir" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: **** includedir: $includedir" >&5
+printf "%s\n" "$as_me: **** includedir: $includedir" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: **** datarootdir: $datarootdir" >&5
+printf "%s\n" "$as_me: **** datarootdir: $datarootdir" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: **** datadir: $datadir" >&5
+printf "%s\n" "$as_me: **** datadir: $datadir" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: **** docdir: ${datarootdir}/doc/$program_name" >&5
+printf "%s\n" "$as_me: **** docdir: ${datarootdir}/doc/$program_name" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: **** htmldir: $htmldir" >&5
+printf "%s\n" "$as_me: **** htmldir: $htmldir" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: **** Executable will be named $program_name" >&5
+printf "%s\n" "$as_me: **** Executable will be named $program_name" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: **** As of PLUMED 2.5, you cannot change paths anymore during \"make install\"" >&5
+printf "%s\n" "$as_me: **** As of PLUMED 2.5, you cannot change paths anymore during \"make install\"" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: **** Please configure and make clean to change the prefix" >&5
+printf "%s\n" "$as_me: **** Please configure and make clean to change the prefix" >&6;}
 
 if test -z "$BASH_COMPLETION_DIR" ; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: **** Bash completion for plumed will not be installed, please add the following two lines to your bashrc" >&5
-$as_echo "$as_me: WARNING: **** Bash completion for plumed will not be installed, please add the following two lines to your bashrc" >&2;}
-  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: **** _$program_name() { eval \"\$($program_name --no-mpi completion 2>/dev/null)\";}" >&5
-$as_echo "$as_me: WARNING: **** _$program_name() { eval \"\$($program_name --no-mpi completion 2>/dev/null)\";}" >&2;}
-  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: **** complete -F _$program_name -o default $program_name" >&5
-$as_echo "$as_me: WARNING: **** complete -F _$program_name -o default $program_name" >&2;}
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: **** Bash completion for plumed will not be installed, please add the following two lines to your bashrc" >&5
+printf "%s\n" "$as_me: WARNING: **** Bash completion for plumed will not be installed, please add the following two lines to your bashrc" >&2;}
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: **** _$program_name() { eval \"\$($program_name --no-mpi completion 2>/dev/null)\";}" >&5
+printf "%s\n" "$as_me: WARNING: **** _$program_name() { eval \"\$($program_name --no-mpi completion 2>/dev/null)\";}" >&2;}
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: **** complete -F _$program_name -o default $program_name" >&5
+printf "%s\n" "$as_me: WARNING: **** complete -F _$program_name -o default $program_name" >&2;}
 fi
 
 if test $mpi = true; then
   if test $mpi_found = ok; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: **** PLUMED will be compiled using MPI" >&5
-$as_echo "$as_me: **** PLUMED will be compiled using MPI" >&6;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: **** PLUMED will be compiled using MPI" >&5
+printf "%s\n" "$as_me: **** PLUMED will be compiled using MPI" >&6;}
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: **** PLUMED will NOT be compiled using MPI because MPI have not been found!" >&5
-$as_echo "$as_me: WARNING: **** PLUMED will NOT be compiled using MPI because MPI have not been found!" >&2;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: **** PLUMED will NOT be compiled using MPI because MPI have not been found!" >&5
+printf "%s\n" "$as_me: WARNING: **** PLUMED will NOT be compiled using MPI because MPI have not been found!" >&2;}
   fi
 else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: **** PLUMED will be compiled without MPI" >&5
-$as_echo "$as_me: **** PLUMED will be compiled without MPI" >&6;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: **** PLUMED will be compiled without MPI" >&5
+printf "%s\n" "$as_me: **** PLUMED will be compiled without MPI" >&6;}
 fi
 
 if test $program_can_run = no ; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: plumed executable will not run on this machine" >&5
-$as_echo "$as_me: WARNING: plumed executable will not run on this machine" >&2;}
-  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: to patch an MD code use 'plumed-patch'" >&5
-$as_echo "$as_me: WARNING: to patch an MD code use 'plumed-patch'" >&2;}
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: plumed executable will not run on this machine" >&5
+printf "%s\n" "$as_me: WARNING: plumed executable will not run on this machine" >&2;}
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: to patch an MD code use 'plumed-patch'" >&5
+printf "%s\n" "$as_me: WARNING: to patch an MD code use 'plumed-patch'" >&2;}
 elif test $mpi_found = ok ; then
   if test $program_can_run_mpi = no ; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: plumed executable will not run on this machine" >&5
-$as_echo "$as_me: WARNING: plumed executable will not run on this machine" >&2;}
-    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: unless you invoke it as 'plumed --no-mpi'" >&5
-$as_echo "$as_me: WARNING: unless you invoke it as 'plumed --no-mpi'" >&2;}
-    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: all command line tools are thus available as 'plumed --no-mpi name-of-the-tool'" >&5
-$as_echo "$as_me: WARNING: all command line tools are thus available as 'plumed --no-mpi name-of-the-tool'" >&2;}
-    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: e.g. 'plumed --no-mpi driver'" >&5
-$as_echo "$as_me: WARNING: e.g. 'plumed --no-mpi driver'" >&2;}
-    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: to patch an MD code use 'plumed --no-mpi patch'" >&5
-$as_echo "$as_me: WARNING: to patch an MD code use 'plumed --no-mpi patch'" >&2;}
-    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: (notice that MPI will be available anyway in the patched code)" >&5
-$as_echo "$as_me: WARNING: (notice that MPI will be available anyway in the patched code)" >&2;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: plumed executable will not run on this machine" >&5
+printf "%s\n" "$as_me: WARNING: plumed executable will not run on this machine" >&2;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: unless you invoke it as 'plumed --no-mpi'" >&5
+printf "%s\n" "$as_me: WARNING: unless you invoke it as 'plumed --no-mpi'" >&2;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: all command line tools are thus available as 'plumed --no-mpi name-of-the-tool'" >&5
+printf "%s\n" "$as_me: WARNING: all command line tools are thus available as 'plumed --no-mpi name-of-the-tool'" >&2;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: e.g. 'plumed --no-mpi driver'" >&5
+printf "%s\n" "$as_me: WARNING: e.g. 'plumed --no-mpi driver'" >&2;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: to patch an MD code use 'plumed --no-mpi patch'" >&5
+printf "%s\n" "$as_me: WARNING: to patch an MD code use 'plumed --no-mpi patch'" >&2;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: (notice that MPI will be available anyway in the patched code)" >&5
+printf "%s\n" "$as_me: WARNING: (notice that MPI will be available anyway in the patched code)" >&2;}
   fi
 fi
 
@@ -11022,8 +11980,8 @@ cat >confcache <<\_ACEOF
 # config.status only pays attention to the cache file if you give it
 # the --recheck option to rerun configure.
 #
-# `ac_cv_env_foo' variables (set or unset) will be overridden when
-# loading this file, other *unset* `ac_cv_foo' will be assigned the
+# 'ac_cv_env_foo' variables (set or unset) will be overridden when
+# loading this file, other *unset* 'ac_cv_foo' will be assigned the
 # following values.
 
 _ACEOF
@@ -11039,8 +11997,8 @@ _ACEOF
     case $ac_val in #(
     *${as_nl}*)
       case $ac_var in #(
-      *_cv_*) { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cache variable $ac_var contains a newline" >&5
-$as_echo "$as_me: WARNING: cache variable $ac_var contains a newline" >&2;} ;;
+      *_cv_*) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: cache variable $ac_var contains a newline" >&5
+printf "%s\n" "$as_me: WARNING: cache variable $ac_var contains a newline" >&2;} ;;
       esac
       case $ac_var in #(
       _ | IFS | as_nl) ;; #(
@@ -11053,14 +12011,14 @@ $as_echo "$as_me: WARNING: cache variable $ac_var contains a newline" >&2;} ;;
   (set) 2>&1 |
     case $as_nl`(ac_space=' '; set) 2>&1` in #(
     *${as_nl}ac_space=\ *)
-      # `set' does not quote correctly, so add quotes: double-quote
+      # 'set' does not quote correctly, so add quotes: double-quote
       # substitution turns \\\\ into \\, and sed turns \\ into \.
       sed -n \
 	"s/'/'\\\\''/g;
 	  s/^\\([_$as_cr_alnum]*_cv_[_$as_cr_alnum]*\\)=\\(.*\\)/\\1='\\2'/p"
       ;; #(
     *)
-      # `set' quotes correctly as required by POSIX, so do not add quotes.
+      # 'set' quotes correctly as required by POSIX, so do not add quotes.
       sed -n "/^[_$as_cr_alnum]*_cv_[_$as_cr_alnum]*=/p"
       ;;
     esac |
@@ -11070,15 +12028,15 @@ $as_echo "$as_me: WARNING: cache variable $ac_var contains a newline" >&2;} ;;
      /^ac_cv_env_/b end
      t clear
      :clear
-     s/^\([^=]*\)=\(.*[{}].*\)$/test "${\1+set}" = set || &/
+     s/^\([^=]*\)=\(.*[{}].*\)$/test ${\1+y} || &/
      t end
      s/^\([^=]*\)=\(.*\)$/\1=${\1=\2}/
      :end' >>confcache
 if diff "$cache_file" confcache >/dev/null 2>&1; then :; else
   if test -w "$cache_file"; then
     if test "x$cache_file" != "x/dev/null"; then
-      { $as_echo "$as_me:${as_lineno-$LINENO}: updating cache $cache_file" >&5
-$as_echo "$as_me: updating cache $cache_file" >&6;}
+      { printf "%s\n" "$as_me:${as_lineno-$LINENO}: updating cache $cache_file" >&5
+printf "%s\n" "$as_me: updating cache $cache_file" >&6;}
       if test ! -f "$cache_file" || test -h "$cache_file"; then
 	cat confcache >"$cache_file"
       else
@@ -11092,8 +12050,8 @@ $as_echo "$as_me: updating cache $cache_file" >&6;}
       fi
     fi
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: not updating unwritable cache $cache_file" >&5
-$as_echo "$as_me: not updating unwritable cache $cache_file" >&6;}
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: not updating unwritable cache $cache_file" >&5
+printf "%s\n" "$as_me: not updating unwritable cache $cache_file" >&6;}
   fi
 fi
 rm -f confcache
@@ -11124,9 +12082,7 @@ s/^[	 ]*#[	 ]*define[	 ][	 ]*\([^	 ][^	 ]*\)[	 ]*\(.*\)/-D\1=\2/g
 t quote
 b any
 :quote
-s/[	 `~#$^&*(){}\\|;'\''"<>?]/\\&/g
-s/\[/\\&/g
-s/\]/\\&/g
+s/[][	 `~#$^&*(){}\\|;'\''"<>?]/\\&/g
 s/\$/$$/g
 H
 :any
@@ -11146,7 +12102,7 @@ U=
 for ac_i in : $LIBOBJS; do test "x$ac_i" = x: && continue
   # 1. Remove the extension, and $U if already installed.
   ac_script='s/\$U\././;s/\.o$//;s/\.obj$//'
-  ac_i=`$as_echo "$ac_i" | sed "$ac_script"`
+  ac_i=`printf "%s\n" "$ac_i" | sed "$ac_script"`
   # 2. Prepend LIBOBJDIR.  When used with automake>=1.10 LIBOBJDIR
   #    will be set to the directory where LIBOBJS objects are built.
   as_fn_append ac_libobjs " \${LIBOBJDIR}$ac_i\$U.$ac_objext"
@@ -11162,8 +12118,8 @@ LTLIBOBJS=$ac_ltlibobjs
 ac_write_fail=0
 ac_clean_files_save=$ac_clean_files
 ac_clean_files="$ac_clean_files $CONFIG_STATUS"
-{ $as_echo "$as_me:${as_lineno-$LINENO}: creating $CONFIG_STATUS" >&5
-$as_echo "$as_me: creating $CONFIG_STATUS" >&6;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: creating $CONFIG_STATUS" >&5
+printf "%s\n" "$as_me: creating $CONFIG_STATUS" >&6;}
 as_write_fail=0
 cat >$CONFIG_STATUS <<_ASEOF || as_write_fail=1
 #! $SHELL
@@ -11186,63 +12142,65 @@ cat >>$CONFIG_STATUS <<\_ASEOF || as_write_fail=1
 
 # Be more Bourne compatible
 DUALCASE=1; export DUALCASE # for MKS sh
-if test -n "${ZSH_VERSION+set}" && (emulate sh) >/dev/null 2>&1; then :
+if test ${ZSH_VERSION+y} && (emulate sh) >/dev/null 2>&1
+then :
   emulate sh
   NULLCMD=:
   # Pre-4.2 versions of Zsh do word splitting on ${1+"$@"}, which
   # is contrary to our usage.  Disable this feature.
   alias -g '${1+"$@"}'='"$@"'
   setopt NO_GLOB_SUBST
-else
-  case `(set -o) 2>/dev/null` in #(
+else case e in #(
+  e) case `(set -o) 2>/dev/null` in #(
   *posix*) :
     set -o posix ;; #(
   *) :
      ;;
+esac ;;
 esac
 fi
 
 
+
+# Reset variables that may have inherited troublesome values from
+# the environment.
+
+# IFS needs to be set, to space, tab, and newline, in precisely that order.
+# (If _AS_PATH_WALK were called with IFS unset, it would have the
+# side effect of setting IFS to empty, thus disabling word splitting.)
+# Quoting is to prevent editors from complaining about space-tab.
 as_nl='
 '
 export as_nl
-# Printing a long string crashes Solaris 7 /usr/bin/printf.
-as_echo='\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\'
-as_echo=$as_echo$as_echo$as_echo$as_echo$as_echo
-as_echo=$as_echo$as_echo$as_echo$as_echo$as_echo$as_echo
-# Prefer a ksh shell builtin over an external printf program on Solaris,
-# but without wasting forks for bash or zsh.
-if test -z "$BASH_VERSION$ZSH_VERSION" \
-    && (test "X`print -r -- $as_echo`" = "X$as_echo") 2>/dev/null; then
-  as_echo='print -r --'
-  as_echo_n='print -rn --'
-elif (test "X`printf %s $as_echo`" = "X$as_echo") 2>/dev/null; then
-  as_echo='printf %s\n'
-  as_echo_n='printf %s'
-else
-  if test "X`(/usr/ucb/echo -n -n $as_echo) 2>/dev/null`" = "X-n $as_echo"; then
-    as_echo_body='eval /usr/ucb/echo -n "$1$as_nl"'
-    as_echo_n='/usr/ucb/echo -n'
-  else
-    as_echo_body='eval expr "X$1" : "X\\(.*\\)"'
-    as_echo_n_body='eval
-      arg=$1;
-      case $arg in #(
-      *"$as_nl"*)
-	expr "X$arg" : "X\\(.*\\)$as_nl";
-	arg=`expr "X$arg" : ".*$as_nl\\(.*\\)"`;;
-      esac;
-      expr "X$arg" : "X\\(.*\\)" | tr -d "$as_nl"
-    '
-    export as_echo_n_body
-    as_echo_n='sh -c $as_echo_n_body as_echo'
-  fi
-  export as_echo_body
-  as_echo='sh -c $as_echo_body as_echo'
-fi
+IFS=" ""	$as_nl"
+
+PS1='$ '
+PS2='> '
+PS4='+ '
+
+# Ensure predictable behavior from utilities with locale-dependent output.
+LC_ALL=C
+export LC_ALL
+LANGUAGE=C
+export LANGUAGE
+
+# We cannot yet rely on "unset" to work, but we need these variables
+# to be unset--not just set to an empty or harmless value--now, to
+# avoid bugs in old shells (e.g. pre-3.0 UWIN ksh).  This construct
+# also avoids known problems related to "unset" and subshell syntax
+# in other old shells (e.g. bash 2.01 and pdksh 5.2.14).
+for as_var in BASH_ENV ENV MAIL MAILPATH CDPATH
+do eval test \${$as_var+y} \
+  && ( (unset $as_var) || exit 1) >/dev/null 2>&1 && unset $as_var || :
+done
+
+# Ensure that fds 0, 1, and 2 are open.
+if (exec 3>&0) 2>/dev/null; then :; else exec 0</dev/null; fi
+if (exec 3>&1) 2>/dev/null; then :; else exec 1>/dev/null; fi
+if (exec 3>&2)            ; then :; else exec 2>/dev/null; fi
 
 # The user is always right.
-if test "${PATH_SEPARATOR+set}" != set; then
+if ${PATH_SEPARATOR+false} :; then
   PATH_SEPARATOR=:
   (PATH='/bin;/bin'; FPATH=$PATH; sh -c :) >/dev/null 2>&1 && {
     (PATH='/bin:/bin'; FPATH=$PATH; sh -c :) >/dev/null 2>&1 ||
@@ -11251,13 +12209,6 @@ if test "${PATH_SEPARATOR+set}" != set; then
 fi
 
 
-# IFS
-# We need space, tab and new line, in precisely that order.  Quoting is
-# there to prevent editors from complaining about space-tab.
-# (If _AS_PATH_WALK were called with IFS unset, it would disable word
-# splitting by setting IFS to empty value.)
-IFS=" ""	$as_nl"
-
 # Find who we are.  Look in the path if we contain no directory separator.
 as_myself=
 case $0 in #((
@@ -11266,43 +12217,27 @@ case $0 in #((
 for as_dir in $PATH
 do
   IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
-    test -r "$as_dir/$0" && as_myself=$as_dir/$0 && break
+  case $as_dir in #(((
+    '') as_dir=./ ;;
+    */) ;;
+    *) as_dir=$as_dir/ ;;
+  esac
+    test -r "$as_dir$0" && as_myself=$as_dir$0 && break
   done
 IFS=$as_save_IFS
 
      ;;
 esac
-# We did not find ourselves, most probably we were run as `sh COMMAND'
+# We did not find ourselves, most probably we were run as 'sh COMMAND'
 # in which case we are not to be found in the path.
 if test "x$as_myself" = x; then
   as_myself=$0
 fi
 if test ! -f "$as_myself"; then
-  $as_echo "$as_myself: error: cannot find myself; rerun with an absolute file name" >&2
+  printf "%s\n" "$as_myself: error: cannot find myself; rerun with an absolute file name" >&2
   exit 1
 fi
 
-# Unset variables that we do not need and which cause bugs (e.g. in
-# pre-3.0 UWIN ksh).  But do not cause bugs in bash 2.01; the "|| exit 1"
-# suppresses any "Segmentation fault" message there.  '((' could
-# trigger a bug in pdksh 5.2.14.
-for as_var in BASH_ENV ENV MAIL MAILPATH
-do eval test x\${$as_var+set} = xset \
-  && ( (unset $as_var) || exit 1) >/dev/null 2>&1 && unset $as_var || :
-done
-PS1='$ '
-PS2='> '
-PS4='+ '
-
-# NLS nuisances.
-LC_ALL=C
-export LC_ALL
-LANGUAGE=C
-export LANGUAGE
-
-# CDPATH.
-(unset CDPATH) >/dev/null 2>&1 && unset CDPATH
 
 
 # as_fn_error STATUS ERROR [LINENO LOG_FD]
@@ -11315,9 +12250,9 @@ as_fn_error ()
   as_status=$1; test $as_status -eq 0 && as_status=1
   if test "$4"; then
     as_lineno=${as_lineno-"$3"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
-    $as_echo "$as_me:${as_lineno-$LINENO}: error: $2" >&$4
+    printf "%s\n" "$as_me:${as_lineno-$LINENO}: error: $2" >&$4
   fi
-  $as_echo "$as_me: error: $2" >&2
+  printf "%s\n" "$as_me: error: $2" >&2
   as_fn_exit $as_status
 } # as_fn_error
 
@@ -11348,22 +12283,25 @@ as_fn_unset ()
   { eval $1=; unset $1;}
 }
 as_unset=as_fn_unset
+
 # as_fn_append VAR VALUE
 # ----------------------
 # Append the text in VALUE to the end of the definition contained in VAR. Take
 # advantage of any shell optimizations that allow amortized linear growth over
 # repeated appends, instead of the typical quadratic growth present in naive
 # implementations.
-if (eval "as_var=1; as_var+=2; test x\$as_var = x12") 2>/dev/null; then :
+if (eval "as_var=1; as_var+=2; test x\$as_var = x12") 2>/dev/null
+then :
   eval 'as_fn_append ()
   {
     eval $1+=\$2
   }'
-else
-  as_fn_append ()
+else case e in #(
+  e) as_fn_append ()
   {
     eval $1=\$$1\$2
-  }
+  } ;;
+esac
 fi # as_fn_append
 
 # as_fn_arith ARG...
@@ -11371,16 +12309,18 @@ fi # as_fn_append
 # Perform arithmetic evaluation on the ARGs, and store the result in the
 # global $as_val. Take advantage of shells that can avoid forks. The arguments
 # must be portable across $(()) and expr.
-if (eval "test \$(( 1 + 1 )) = 2") 2>/dev/null; then :
+if (eval "test \$(( 1 + 1 )) = 2") 2>/dev/null
+then :
   eval 'as_fn_arith ()
   {
     as_val=$(( $* ))
   }'
-else
-  as_fn_arith ()
+else case e in #(
+  e) as_fn_arith ()
   {
     as_val=`expr "$@" || test $? -eq 1`
-  }
+  } ;;
+esac
 fi # as_fn_arith
 
 
@@ -11407,7 +12347,7 @@ as_me=`$as_basename -- "$0" ||
 $as_expr X/"$0" : '.*/\([^/][^/]*\)/*$' \| \
 	 X"$0" : 'X\(//\)$' \| \
 	 X"$0" : 'X\(/\)' \| . 2>/dev/null ||
-$as_echo X/"$0" |
+printf "%s\n" X/"$0" |
     sed '/^.*\/\([^/][^/]*\)\/*$/{
 	    s//\1/
 	    q
@@ -11429,6 +12369,10 @@ as_cr_Letters=$as_cr_letters$as_cr_LETTERS
 as_cr_digits='0123456789'
 as_cr_alnum=$as_cr_Letters$as_cr_digits
 
+
+# Determine whether it's possible to make 'echo' print without a newline.
+# These variables are no longer used directly by Autoconf, but are AC_SUBSTed
+# for compatibility with existing Makefiles.
 ECHO_C= ECHO_N= ECHO_T=
 case `echo -n x` in #(((((
 -n*)
@@ -11442,6 +12386,12 @@ case `echo -n x` in #(((((
   ECHO_N='-n';;
 esac
 
+# For backward compatibility with old third-party macros, we provide
+# the shell variables $as_echo and $as_echo_n.  New code should use
+# AS_ECHO(["message"]) and AS_ECHO_N(["message"]), respectively.
+as_echo='printf %s\n'
+as_echo_n='printf %s'
+
 rm -f conf$$ conf$$.exe conf$$.file
 if test -d conf$$.dir; then
   rm -f conf$$.dir/conf$$.file
@@ -11453,9 +12403,9 @@ if (echo >conf$$.file) 2>/dev/null; then
   if ln -s conf$$.file conf$$ 2>/dev/null; then
     as_ln_s='ln -s'
     # ... but there are two gotchas:
-    # 1) On MSYS, both `ln -s file dir' and `ln file dir' fail.
-    # 2) DJGPP < 2.04 has no symlinks; `ln -s' creates a wrapper executable.
-    # In both cases, we have to default to `cp -pR'.
+    # 1) On MSYS, both 'ln -s file dir' and 'ln file dir' fail.
+    # 2) DJGPP < 2.04 has no symlinks; 'ln -s' creates a wrapper executable.
+    # In both cases, we have to default to 'cp -pR'.
     ln -s conf$$.file conf$$.dir 2>/dev/null && test ! -f conf$$.exe ||
       as_ln_s='cp -pR'
   elif ln conf$$.file conf$$ 2>/dev/null; then
@@ -11483,7 +12433,7 @@ as_fn_mkdir_p ()
     as_dirs=
     while :; do
       case $as_dir in #(
-      *\'*) as_qdir=`$as_echo "$as_dir" | sed "s/'/'\\\\\\\\''/g"`;; #'(
+      *\'*) as_qdir=`printf "%s\n" "$as_dir" | sed "s/'/'\\\\\\\\''/g"`;; #'(
       *) as_qdir=$as_dir;;
       esac
       as_dirs="'$as_qdir' $as_dirs"
@@ -11492,7 +12442,7 @@ $as_expr X"$as_dir" : 'X\(.*[^/]\)//*[^/][^/]*/*$' \| \
 	 X"$as_dir" : 'X\(//\)[^/]' \| \
 	 X"$as_dir" : 'X\(//\)$' \| \
 	 X"$as_dir" : 'X\(/\)' \| . 2>/dev/null ||
-$as_echo X"$as_dir" |
+printf "%s\n" X"$as_dir" |
     sed '/^X\(.*[^/]\)\/\/*[^/][^/]*\/*$/{
 	    s//\1/
 	    q
@@ -11536,10 +12486,12 @@ as_test_x='test -x'
 as_executable_p=as_fn_executable_p
 
 # Sed expression to map a string onto a valid CPP name.
-as_tr_cpp="eval sed 'y%*$as_cr_letters%P$as_cr_LETTERS%;s%[^_$as_cr_alnum]%_%g'"
+as_sed_cpp="y%*$as_cr_letters%P$as_cr_LETTERS%;s%[^_$as_cr_alnum]%_%g"
+as_tr_cpp="eval sed '$as_sed_cpp'" # deprecated
 
 # Sed expression to map a string onto a valid variable name.
-as_tr_sh="eval sed 'y%*+%pp%;s%[^_$as_cr_alnum]%_%g'"
+as_sed_sh="y%*+%pp%;s%[^_$as_cr_alnum]%_%g"
+as_tr_sh="eval sed '$as_sed_sh'" # deprecated
 
 
 exec 6>&1
@@ -11555,7 +12507,7 @@ cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
 # values after options handling.
 ac_log="
 This file was extended by PLUMED $as_me 2, which was
-generated by GNU Autoconf 2.69.  Invocation command line was
+generated by GNU Autoconf 2.72.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
   CONFIG_HEADERS  = $CONFIG_HEADERS
@@ -11582,7 +12534,7 @@ _ACEOF
 
 cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
 ac_cs_usage="\
-\`$as_me' instantiates files and other configuration actions
+'$as_me' instantiates files and other configuration actions
 from templates according to the current configuration.  Unless the files
 and actions are specified as TAGs, all are instantiated by default.
 
@@ -11604,14 +12556,16 @@ $config_files
 Report bugs to the package provider."
 
 _ACEOF
+ac_cs_config=`printf "%s\n" "$ac_configure_args" | sed "$ac_safe_unquote"`
+ac_cs_config_escaped=`printf "%s\n" "$ac_cs_config" | sed "s/^ //; s/'/'\\\\\\\\''/g"`
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
-ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
+ac_cs_config='$ac_cs_config_escaped'
 ac_cs_version="\\
 PLUMED config.status 2
-configured by $0, generated by GNU Autoconf 2.69,
+configured by $0, generated by GNU Autoconf 2.72,
   with options \\"\$ac_cs_config\\"
 
-Copyright (C) 2012 Free Software Foundation, Inc.
+Copyright (C) 2023 Free Software Foundation, Inc.
 This config.status script is free software; the Free Software Foundation
 gives unlimited permission to copy, distribute and modify it."
 
@@ -11648,28 +12602,28 @@ do
   -recheck | --recheck | --rechec | --reche | --rech | --rec | --re | --r)
     ac_cs_recheck=: ;;
   --version | --versio | --versi | --vers | --ver | --ve | --v | -V )
-    $as_echo "$ac_cs_version"; exit ;;
+    printf "%s\n" "$ac_cs_version"; exit ;;
   --config | --confi | --conf | --con | --co | --c )
-    $as_echo "$ac_cs_config"; exit ;;
+    printf "%s\n" "$ac_cs_config"; exit ;;
   --debug | --debu | --deb | --de | --d | -d )
     debug=: ;;
   --file | --fil | --fi | --f )
     $ac_shift
     case $ac_optarg in
-    *\'*) ac_optarg=`$as_echo "$ac_optarg" | sed "s/'/'\\\\\\\\''/g"` ;;
+    *\'*) ac_optarg=`printf "%s\n" "$ac_optarg" | sed "s/'/'\\\\\\\\''/g"` ;;
     '') as_fn_error $? "missing file argument" ;;
     esac
     as_fn_append CONFIG_FILES " '$ac_optarg'"
     ac_need_defaults=false;;
   --he | --h |  --help | --hel | -h )
-    $as_echo "$ac_cs_usage"; exit ;;
+    printf "%s\n" "$ac_cs_usage"; exit ;;
   -q | -quiet | --quiet | --quie | --qui | --qu | --q \
   | -silent | --silent | --silen | --sile | --sil | --si | --s)
     ac_cs_silent=: ;;
 
   # This is an error.
-  -*) as_fn_error $? "unrecognized option: \`$1'
-Try \`$0 --help' for more information." ;;
+  -*) as_fn_error $? "unrecognized option: '$1'
+Try '$0 --help' for more information." ;;
 
   *) as_fn_append ac_config_targets " $1"
      ac_need_defaults=false ;;
@@ -11690,7 +12644,7 @@ cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 if \$ac_cs_recheck; then
   set X $SHELL '$0' $ac_configure_args \$ac_configure_extra_args --no-create --no-recursion
   shift
-  \$as_echo "running CONFIG_SHELL=$SHELL \$*" >&6
+  \printf "%s\n" "running CONFIG_SHELL=$SHELL \$*" >&6
   CONFIG_SHELL='$SHELL'
   export CONFIG_SHELL
   exec "\$@"
@@ -11704,7 +12658,7 @@ exec 5>>config.log
   sed 'h;s/./-/g;s/^.../## /;s/...$/ ##/;p;x;p;x' <<_ASBOX
 ## Running $as_me. ##
 _ASBOX
-  $as_echo "$ac_log"
+  printf "%s\n" "$ac_log"
 } >&5
 
 _ACEOF
@@ -11721,7 +12675,7 @@ do
     "sourceme.sh") CONFIG_FILES="$CONFIG_FILES sourceme.sh" ;;
     "stamp-h") CONFIG_FILES="$CONFIG_FILES stamp-h" ;;
 
-  *) as_fn_error $? "invalid argument: \`$ac_config_target'" "$LINENO" 5;;
+  *) as_fn_error $? "invalid argument: '$ac_config_target'" "$LINENO" 5;;
   esac
 done
 
@@ -11731,7 +12685,7 @@ done
 # We use the long form for the default assignment because of an extremely
 # bizarre bug on SunOS 4.1.3.
 if $ac_need_defaults; then
-  test "${CONFIG_FILES+set}" = set || CONFIG_FILES=$config_files
+  test ${CONFIG_FILES+y} || CONFIG_FILES=$config_files
 fi
 
 # Have a temporary directory for convenience.  Make it in the build tree
@@ -11739,7 +12693,7 @@ fi
 # creating and moving files from /tmp can sometimes cause problems.
 # Hook for its removal unless debugging.
 # Note that there is a small window in which the directory will not be cleaned:
-# after its creation but before its name has been assigned to `$tmp'.
+# after its creation but before its name has been assigned to '$tmp'.
 $debug ||
 {
   tmp= ac_tmp=
@@ -11763,7 +12717,7 @@ ac_tmp=$tmp
 
 # Set up the scripts for CONFIG_FILES section.
 # No need to generate them if there are no CONFIG_FILES.
-# This happens for instance with `./config.status config.h'.
+# This happens for instance with './config.status config.h'.
 if test -n "$CONFIG_FILES"; then
 
 
@@ -11929,7 +12883,7 @@ do
   esac
   case $ac_mode$ac_tag in
   :[FHL]*:*);;
-  :L* | :C*:*) as_fn_error $? "invalid tag \`$ac_tag'" "$LINENO" 5;;
+  :L* | :C*:*) as_fn_error $? "invalid tag '$ac_tag'" "$LINENO" 5;;
   :[FH]-) ac_tag=-:-;;
   :[FH]*) ac_tag=$ac_tag:$ac_tag.in;;
   esac
@@ -11951,33 +12905,33 @@ do
       -) ac_f="$ac_tmp/stdin";;
       *) # Look for the file first in the build tree, then in the source tree
 	 # (if the path is not absolute).  The absolute path cannot be DOS-style,
-	 # because $ac_f cannot contain `:'.
+	 # because $ac_f cannot contain ':'.
 	 test -f "$ac_f" ||
 	   case $ac_f in
 	   [\\/$]*) false;;
 	   *) test -f "$srcdir/$ac_f" && ac_f="$srcdir/$ac_f";;
 	   esac ||
-	   as_fn_error 1 "cannot find input file: \`$ac_f'" "$LINENO" 5;;
+	   as_fn_error 1 "cannot find input file: '$ac_f'" "$LINENO" 5;;
       esac
-      case $ac_f in *\'*) ac_f=`$as_echo "$ac_f" | sed "s/'/'\\\\\\\\''/g"`;; esac
+      case $ac_f in *\'*) ac_f=`printf "%s\n" "$ac_f" | sed "s/'/'\\\\\\\\''/g"`;; esac
       as_fn_append ac_file_inputs " '$ac_f'"
     done
 
-    # Let's still pretend it is `configure' which instantiates (i.e., don't
+    # Let's still pretend it is 'configure' which instantiates (i.e., don't
     # use $as_me), people would be surprised to read:
     #    /* config.h.  Generated by config.status.  */
     configure_input='Generated from '`
-	  $as_echo "$*" | sed 's|^[^:]*/||;s|:[^:]*/|, |g'
+	  printf "%s\n" "$*" | sed 's|^[^:]*/||;s|:[^:]*/|, |g'
 	`' by configure.'
     if test x"$ac_file" != x-; then
       configure_input="$ac_file.  $configure_input"
-      { $as_echo "$as_me:${as_lineno-$LINENO}: creating $ac_file" >&5
-$as_echo "$as_me: creating $ac_file" >&6;}
+      { printf "%s\n" "$as_me:${as_lineno-$LINENO}: creating $ac_file" >&5
+printf "%s\n" "$as_me: creating $ac_file" >&6;}
     fi
     # Neutralize special characters interpreted by sed in replacement strings.
     case $configure_input in #(
     *\&* | *\|* | *\\* )
-       ac_sed_conf_input=`$as_echo "$configure_input" |
+       ac_sed_conf_input=`printf "%s\n" "$configure_input" |
        sed 's/[\\\\&|]/\\\\&/g'`;; #(
     *) ac_sed_conf_input=$configure_input;;
     esac
@@ -11994,7 +12948,7 @@ $as_expr X"$ac_file" : 'X\(.*[^/]\)//*[^/][^/]*/*$' \| \
 	 X"$ac_file" : 'X\(//\)[^/]' \| \
 	 X"$ac_file" : 'X\(//\)$' \| \
 	 X"$ac_file" : 'X\(/\)' \| . 2>/dev/null ||
-$as_echo X"$ac_file" |
+printf "%s\n" X"$ac_file" |
     sed '/^X\(.*[^/]\)\/\/*[^/][^/]*\/*$/{
 	    s//\1/
 	    q
@@ -12018,9 +12972,9 @@ $as_echo X"$ac_file" |
 case "$ac_dir" in
 .) ac_dir_suffix= ac_top_builddir_sub=. ac_top_build_prefix= ;;
 *)
-  ac_dir_suffix=/`$as_echo "$ac_dir" | sed 's|^\.[\\/]||'`
+  ac_dir_suffix=/`printf "%s\n" "$ac_dir" | sed 's|^\.[\\/]||'`
   # A ".." for each directory in $ac_dir_suffix.
-  ac_top_builddir_sub=`$as_echo "$ac_dir_suffix" | sed 's|/[^\\/]*|/..|g;s|/||'`
+  ac_top_builddir_sub=`printf "%s\n" "$ac_dir_suffix" | sed 's|/[^\\/]*|/..|g;s|/||'`
   case $ac_top_builddir_sub in
   "") ac_top_builddir_sub=. ac_top_build_prefix= ;;
   *)  ac_top_build_prefix=$ac_top_builddir_sub/ ;;
@@ -12073,8 +13027,8 @@ ac_sed_dataroot='
 case `eval "sed -n \"\$ac_sed_dataroot\" $ac_file_inputs"` in
 *datarootdir*) ac_datarootdir_seen=yes;;
 *@datadir@*|*@docdir@*|*@infodir@*|*@localedir@*|*@mandir@*)
-  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: $ac_file_inputs seems to ignore the --datarootdir setting" >&5
-$as_echo "$as_me: WARNING: $ac_file_inputs seems to ignore the --datarootdir setting" >&2;}
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: $ac_file_inputs seems to ignore the --datarootdir setting" >&5
+printf "%s\n" "$as_me: WARNING: $ac_file_inputs seems to ignore the --datarootdir setting" >&2;}
 _ACEOF
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
   ac_datarootdir_hack='
@@ -12087,7 +13041,7 @@ cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 esac
 _ACEOF
 
-# Neutralize VPATH when `$srcdir' = `.'.
+# Neutralize VPATH when '$srcdir' = '.'.
 # Shell code in configure.ac might set extrasub.
 # FIXME: do we really want to maintain this feature?
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
@@ -12116,9 +13070,9 @@ test -z "$ac_datarootdir_hack$ac_datarootdir_seen" &&
   { ac_out=`sed -n '/\${datarootdir}/p' "$ac_tmp/out"`; test -n "$ac_out"; } &&
   { ac_out=`sed -n '/^[	 ]*datarootdir[	 ]*:*=/p' \
       "$ac_tmp/out"`; test -z "$ac_out"; } &&
-  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: $ac_file contains a reference to the variable \`datarootdir'
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: $ac_file contains a reference to the variable 'datarootdir'
 which seems to be undefined.  Please make sure it is defined" >&5
-$as_echo "$as_me: WARNING: $ac_file contains a reference to the variable \`datarootdir'
+printf "%s\n" "$as_me: WARNING: $ac_file contains a reference to the variable 'datarootdir'
 which seems to be undefined.  Please make sure it is defined" >&2;}
 
   rm -f "$ac_tmp/stdin"
@@ -12170,8 +13124,9 @@ if test "$no_create" != yes; then
   $ac_cs_success || as_fn_exit 1
 fi
 if test -n "$ac_unrecognized_opts" && test "$enable_option_checking" != no; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: unrecognized options: $ac_unrecognized_opts" >&5
-$as_echo "$as_me: WARNING: unrecognized options: $ac_unrecognized_opts" >&2;}
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: unrecognized options: $ac_unrecognized_opts" >&5
+printf "%s\n" "$as_me: WARNING: unrecognized options: $ac_unrecognized_opts" >&2;}
 fi
 
 
+
diff --git a/configure.ac b/configure.ac
index ed5d4e0a5d..ad5bf2d002 100644
--- a/configure.ac
+++ b/configure.ac
@@ -324,6 +324,7 @@ PLUMED_CONFIG_ENABLE([af_ocl],[search for arrayfire_ocl],[no])
 PLUMED_CONFIG_ENABLE([af_cuda],[search for arrayfire_cuda],[no])
 PLUMED_CONFIG_ENABLE([af_cpu],[search for arrayfire_cpu],[no])
 PLUMED_CONFIG_ENABLE([libtorch],[search for libtorch],[no]) #added by luigibonati
+PLUMED_CONFIG_ENABLE([metatensor],[search for metatensor],[no])
 
 AC_ARG_VAR(SOEXT,[extension of dynamic libraries (so/dylib)])
 AC_ARG_VAR(STATIC_LIBS,[variables that should be linked statically directly to MD code - configure will add here -ldl if necessary ])
@@ -928,6 +929,11 @@ if test "$af_cpu" = true ; then
   PLUMED_CHECK_PACKAGE([arrayfire.h],[af_is_double],[__PLUMED_HAS_ARRAYFIRE],[afcpu])
 fi
 
+# metatensor requires libtorch
+if test $metatensor = true ; then
+  libtorch=true;
+fi
+
 #added by luigibonati
 if test $libtorch = true ; then 
   # disable as-needed in linking libraries (both static and shared)
@@ -965,6 +971,17 @@ if test $libtorch = true ; then
   fi
 fi
 
+if test $metatensor = true ; then
+  # find metatensor and metatensor_torch
+  PLUMED_CHECK_CXX_PACKAGE([metatensor],[
+    #include <metatensor/torch.hpp>
+    int main() {
+      metatensor_torch::version();
+      return 0;
+    }
+  ], [__PLUMED_HAS_METATENSOR], [metatensor metatensor_torch], [true])
+fi
+
 # in non-debug mode, add -DNDEBUG
 if test "$debug" = false ; then
   AC_MSG_NOTICE([Release mode, adding -DNDEBUG])
diff --git a/src/.gitignore b/src/.gitignore
index 6a82ca16c2..2ed78adad1 100644
--- a/src/.gitignore
+++ b/src/.gitignore
@@ -64,6 +64,7 @@
 !/s2cm
 !/pytorch
 !/membranefusion
+!/metatensor
 
 # And just ignore these files
 *.xxd
diff --git a/src/metatensor/.gitignore b/src/metatensor/.gitignore
new file mode 100644
index 0000000000..10af78cac2
--- /dev/null
+++ b/src/metatensor/.gitignore
@@ -0,0 +1,12 @@
+/*
+# in this directory, only accept source, Makefile and README
+!/.gitignore
+!/*.c
+!/*.cpp
+!/*.h
+!/*.sh
+!/Makefile
+!/README
+!/README.md
+!/module.type
+!/COPYRIGHT
diff --git a/src/metatensor/Makefile b/src/metatensor/Makefile
new file mode 100644
index 0000000000..fce705eebf
--- /dev/null
+++ b/src/metatensor/Makefile
@@ -0,0 +1,4 @@
+USE=core
+
+#generic makefile
+include ../maketools/make.module
diff --git a/src/metatensor/README.md b/src/metatensor/README.md
new file mode 100644
index 0000000000..4c636371e2
--- /dev/null
+++ b/src/metatensor/README.md
@@ -0,0 +1,68 @@
+# Metatensor module for PLUMED
+
+
+## Building the code
+
+1. You'll need to fist install libtorch, either by installing PyTorch itself
+   with Python, or by downloading the prebuilt C++ library from
+   https://pytorch.org/get-started/locally/.
+
+```bash
+# point this to the path where you extracted the C++ libtorch
+TORCH_PREFIX=../../..
+# if you used Python to install torch, you can do this:
+TORCH_CMAKE_PREFIX=$(python -c "import torch; print(torch.utils.cmake_prefix_path)")
+TORCH_PREFIX=$(cd "$TORCH_CMAKE_PREFIX/../.." && pwd)
+
+# patch a bug from torch's MKL detection
+cd <PLUMED/DIR>
+./src/metatensor/patch-torch.sh "$TORCH_PREFIX"
+```
+
+2. a) build and install metatensor-torch from source. You'll need a rust
+      compiler on your system, the easiest way is by using https://rustup.rs/
+
+```bash
+cd <SOME/PLACE/WHERE/TO/PUT/METATENSOR/SOURCES>
+
+# define a location where metatensor should be installed
+METATENSOR_PREFIX=<...>
+
+METATENSOR_TORCH_PREFIX="$METATENSOR_PREFIX"
+
+git clone https://github.com/lab-cosmo/metatensor --tag metatensor-torch-v0.3.0
+cd metatensor
+
+mkdir build && cd build
+cmake -DBUILD_SHARED_LIBS=ON \
+      -DCMAKE_INSTALL_PREFIX="$METATENSOR_PREFIX" \
+      -DCMAKE_PREFIX_PATH="$TORCH_PREFIX" \
+      -DBUILD_METATENSOR_TORCH=ON \
+      -DMETATENSOR_INSTALL_BOTH_STATIC_SHARED=OFF \
+      ..
+
+cmake --build . --target install --parallel
+```
+
+2. b) alternatively, use metatensor-torch from Python (`pip install metatensor[torch]`)
+
+```bash
+METATENSOR_CMAKE_PREFIX=$(python -c "import metatensor; print(metatensor.utils.cmake_prefix_path)")
+METATENSOR_PREFIX=$(cd "$METATENSOR_CMAKE_PREFIX/../.." && pwd)
+
+METATENSOR_TORCH_CMAKE_PREFIX=$(python -c "import torch; print(torch.utils.cmake_prefix_path)")
+METATENSOR_TORCH_PREFIX=$(cd "$METATENSOR_TORCH_CMAKE_PREFIX/../.." && pwd)
+```
+
+3. build Plumed itself
+
+```bash
+cd <PLUMED/DIR>
+
+# configure with metatensor
+./configure --enable-libtorch --enable-metatensor --enable-modules=+metatensor \
+    LDFLAGS="-L$TORCH_PREFIX/lib -L$METATENSOR_PREFIX/lib -L$METATENSOR_TORCH_PREFIX/lib" \
+    CPPFLAGS="-I$TORCH_PREFIX/include -I$TORCH_PREFIX/include/torch/csrc/api/include -I$METATENSOR_PREFIX/include -I$METATENSOR_TORCH_PREFIX/include"
+
+make -j && make install
+```
diff --git a/src/metatensor/metatensor.cpp b/src/metatensor/metatensor.cpp
new file mode 100644
index 0000000000..e27373ee8f
--- /dev/null
+++ b/src/metatensor/metatensor.cpp
@@ -0,0 +1,80 @@
+/* ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+    Copyright (c) 2024 Guillaume Fraux
+
+    This module is free software: you can redistribute it and/or modify it under
+    the terms of the GNU Lesser General Public License as published by the Free
+    Software Foundation, either version 3 of the License, or (at your option)
+    any later version.
+ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */
+
+#if !defined(__PLUMED_HAS_LIBTORCH) || !defined(__PLUMED_HAS_METATENSOR)
+
+// give a nice error message if the user tries to enable
+// metatensor without enabling the corresponding libraries
+#error "can not compile the metatensor module without the corresponding libraries, either the disable metatensor module or configure with `--enable-metatensor --enable-libtorch` and make sure the libraries can be found"
+
+#else
+
+#include "core/ActionAtomistic.h"
+#include "core/ActionWithValue.h"
+#include "core/ActionRegister.h"
+#include "core/PlumedMain.h"
+
+
+#include <torch/script.h>
+#include <metatensor/torch.hpp>
+
+
+namespace PLMD {
+
+class MetatensorPlumedAction: public ActionAtomistic, public ActionWithValue {
+public:
+    static void registerKeywords(Keywords& keys);
+    explicit MetatensorPlumedAction(const ActionOptions&);
+
+    void calculate() override;
+    void apply() override;
+    unsigned getNumberOfDerivatives() override;
+
+private:
+
+    metatensor_torch::TorchTensorMap output_;
+};
+
+PLUMED_REGISTER_ACTION(MetatensorPlumedAction, "METATENSOR")
+
+void MetatensorPlumedAction::registerKeywords(Keywords& keys) {
+    Action::registerKeywords(keys);
+    ActionAtomistic::registerKeywords(keys);
+    ActionWithValue::registerKeywords(keys);
+
+    throw std::runtime_error("unimplemented");
+}
+
+MetatensorPlumedAction::MetatensorPlumedAction(const ActionOptions& options):
+    Action(options),
+    ActionAtomistic(options),
+    ActionWithValue(options)
+{
+    throw std::runtime_error("unimplemented");
+}
+
+unsigned MetatensorPlumedAction::getNumberOfDerivatives() {
+    // gradients w.r.t. positions (3 x N values) + gradients w.r.t. strain (9 values)
+    return 3 * this->getNumberOfAtoms() + 9;
+}
+
+
+void MetatensorPlumedAction::calculate() {
+    throw std::runtime_error("unimplemented");
+}
+
+
+void MetatensorPlumedAction::apply() {
+    throw std::runtime_error("unimplemented");
+}
+
+} // namespace PLMD
+
+
+#endif
diff --git a/src/metatensor/module.type b/src/metatensor/module.type
new file mode 100644
index 0000000000..de83273033
--- /dev/null
+++ b/src/metatensor/module.type
@@ -0,0 +1 @@
+default-off
diff --git a/src/metatensor/patch-torch.sh b/src/metatensor/patch-torch.sh
new file mode 100755
index 0000000000..8ec7cafac0
--- /dev/null
+++ b/src/metatensor/patch-torch.sh
@@ -0,0 +1,45 @@
+#!/usr/bin/env bash
+
+# This pulls in the fix from https://github.com/pytorch/pytorch/pull/119945
+# until it is properly released
+
+set -eu
+
+TORCH_PREFIX=$1
+
+if [ -f "$TORCH_PREFIX/share/cmake/Caffe2/public/mkl.cmake" ]; then
+    MKL_CMAKE="$TORCH_PREFIX/share/cmake/Caffe2/public/mkl.cmake"
+elif [ -f "$TORCH_PREFIX/Caffe2/public/mkl.cmake" ]; then
+    MKL_CMAKE="$TORCH_PREFIX/Caffe2/public/mkl.cmake"
+else
+    echo "Failed to find mkl.cmake in '$TORCH_PREFIX'"
+    exit 1
+fi
+
+cat > "$MKL_CMAKE" << EOF
+
+find_package(MKL QUIET)
+
+if(TARGET caffe2::mkl)
+  return()
+endif()
+
+add_library(caffe2::mkl INTERFACE IMPORTED)
+target_include_directories(caffe2::mkl INTERFACE \${MKL_INCLUDE_DIR})
+target_link_libraries(caffe2::mkl INTERFACE \${MKL_LIBRARIES})
+foreach(MKL_LIB IN LISTS MKL_LIBRARIES)
+  if(EXISTS "\${MKL_LIB}")
+    get_filename_component(MKL_LINK_DIR "\${MKL_LIB}" DIRECTORY)
+    if(IS_DIRECTORY "\${MKL_LINK_DIR}")
+      target_link_directories(caffe2::mkl INTERFACE "\${MKL_LINK_DIR}")
+    endif()
+  endif()
+endforeach()
+
+# TODO: This is a hack, it will not pick up architecture dependent
+# MKL libraries correctly; see https://github.com/pytorch/pytorch/issues/73008
+set_property(
+  TARGET caffe2::mkl PROPERTY INTERFACE_LINK_DIRECTORIES
+  \${MKL_ROOT}/lib \${MKL_ROOT}/lib/intel64 \${MKL_ROOT}/lib/intel64_win \${MKL_ROOT}/lib/win-x64)
+
+EOF