[INFRA] Use cpp23

.github/workflows/ci_linux.yml

@@ -33,7 +33,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        compiler: ["clang-19", "clang-18", "clang-17", "gcc-14", "gcc-13", "gcc-12", "gcc-11", "intel"]
+        compiler: ["clang-19", "clang-18", "clang-17", "gcc-14", "gcc-13", "gcc-12", "intel"]
         include:
           - compiler: "intel"
             cxx_flags: "-fp-model=strict -Wno-overriding-option"

.github/workflows/ci_macos.yml

@@ -33,7 +33,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        compiler: ["clang-19", "clang-18", "clang-17", "gcc-14", "gcc-13", "gcc-12", "gcc-11"]
+        compiler: ["clang-19", "clang-18", "clang-17", "gcc-14", "gcc-13", "gcc-12"]
     steps:
       - name: Checkout
         uses: actions/checkout@v4

.github/workflows/ci_misc.yml

@@ -33,7 +33,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        compiler: ["clang-19", "gcc-14", "gcc-11", "intel"]
+        compiler: ["clang-19", "gcc-14", "gcc-12", "intel"]
         build: ["snippet", "performance", "header"]
         include:
           - compiler: "intel"

.github/workflows/cron_api.yml

@@ -32,7 +32,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        compiler: ["gcc-14", "gcc-13", "gcc-12", "gcc-11"]
+        compiler: ["gcc-14", "gcc-13", "gcc-12"]
     container:
       image: ghcr.io/seqan/${{ matrix.compiler }}
       volumes:

.github/workflows/cron_avx2.yml

@@ -33,7 +33,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        compiler: ["clang-19", "clang-18", "clang-17", "gcc-14", "gcc-13", "gcc-12", "gcc-11", "intel"]
+        compiler: ["clang-19", "clang-18", "clang-17", "gcc-14", "gcc-13", "gcc-12", "intel"]
         build: [unit, snippet, performance, header]
         include:
           - compiler: "intel"

.github/workflows/cron_latest_libraries.yml

@@ -33,7 +33,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        compiler: ["clang-19", "clang-18", "clang-17", "gcc-14", "gcc-13", "gcc-12", "gcc-11", "intel"]
+        compiler: ["clang-19", "clang-18", "clang-17", "gcc-14", "gcc-13", "gcc-12", "intel"]
         build: [unit, snippet, performance, header]
         include:
           - compiler: "intel"

cmake/package-lock.cmake

@@ -47,8 +47,7 @@ CPMDeclarePackage (googletest
                    VERSION ${SEQAN3_GOOGLETEST_VERSION}
                    GITHUB_REPOSITORY google/googletest
                    SYSTEM TRUE
-                   OPTIONS "BUILD_GMOCK OFF" "INSTALL_GTEST OFF" "CMAKE_CXX_STANDARD 20"
-                           "CMAKE_MESSAGE_LOG_LEVEL WARNING")
+                   OPTIONS "BUILD_GMOCK OFF" "INSTALL_GTEST OFF" "CMAKE_MESSAGE_LOG_LEVEL WARNING")
 # doxygen-awesome
 set (SEQAN3_DOXYGEN_AWESOME_VERSION 2.3.4)
 CPMDeclarePackage (doxygen_awesome

cmake/seqan3-config.cmake

@@ -44,17 +44,15 @@
 #   SEQAN3_INCLUDE_DIRS     -- to be passed to include_directories ()
 #   SEQAN3_LIBRARIES        -- to be passed to target_link_libraries ()
 #   SEQAN3_DEFINITIONS      -- to be passed to add_definitions ()
-#   SEQAN3_CXX_FLAGS        -- to be added to CMAKE_CXX_FLAGS
 #
 # Additionally, the following [IMPORTED][IMPORTED] targets are defined:
 #
 #   seqan3::seqan3          -- interface target where
 #                                  target_link_libraries(target seqan3::seqan3)
 #                              automatically sets
 #                                  target_include_directories(target $SEQAN3_INCLUDE_DIRS),
-#                                  target_link_libraries(target $SEQAN3_LIBRARIES),
-#                                  target_compile_definitions(target $SEQAN3_DEFINITIONS) and
-#                                  target_compile_options(target $SEQAN3_CXX_FLAGS)
+#                                  target_link_libraries(target $SEQAN3_LIBRARIES) and
+#                                  target_compile_definitions(target $SEQAN3_DEFINITIONS)
 #                              for a target.
 #
 #   [IMPORTED]: https://cmake.org/cmake/help/v3.10/prop_tgt/IMPORTED.html#prop_tgt:IMPORTED
@@ -203,53 +201,14 @@ option (SEQAN3_NO_BZIP2 "Don't use BZip2, even if present." OFF)
 # Check supported compilers
 # ----------------------------------------------------------------------------
 
-if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 10)
-    message (FATAL_ERROR "GCC < 10 is not supported. The detected compiler version is ${CMAKE_CXX_COMPILER_VERSION}.")
+if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 12)
+    message (FATAL_ERROR "GCC < 12 is not supported. The detected compiler version is ${CMAKE_CXX_COMPILER_VERSION}.")
 endif ()
 
 if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 17)
     message (FATAL_ERROR "Clang < 17 is not supported. The detected compiler version is ${CMAKE_CXX_COMPILER_VERSION}.")
 endif ()
 
-# ----------------------------------------------------------------------------
-# Require C++20
-# ----------------------------------------------------------------------------
-
-set (CMAKE_REQUIRED_FLAGS_SAVE ${CMAKE_REQUIRED_FLAGS})
-
-set (CXXSTD_TEST_SOURCE
-     "#if !defined (__cplusplus) || (__cplusplus < 202002L)
-      #error NOCXX20
-      #endif
-      int main() {}")
-
-set (SEQAN3_FEATURE_CPP20_FLAG_BUILTIN "")
-set (SEQAN3_FEATURE_CPP20_FLAG_STD20 "-std=c++20")
-
-set (SEQAN3_CPP20_FLAG "")
-
-foreach (_FLAG BUILTIN STD20)
-    set (CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS_SAVE} ${SEQAN3_FEATURE_CPP20_FLAG_${_FLAG}}")
-
-    check_cxx_source_compiles ("${CXXSTD_TEST_SOURCE}" CPP20_FLAG_${_FLAG})
-
-    if (CPP20_FLAG_${_FLAG})
-        set (SEQAN3_CPP20_FLAG ${_FLAG})
-        break ()
-    endif ()
-endforeach ()
-
-set (CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS_SAVE})
-
-if (SEQAN3_CPP20_FLAG STREQUAL "BUILTIN")
-    seqan3_config_print ("C++ Standard-20 support:    builtin")
-elseif (SEQAN3_CPP20_FLAG)
-    set (SEQAN3_CXX_FLAGS "${SEQAN3_CXX_FLAGS} ${SEQAN3_FEATURE_CPP20_FLAG_${SEQAN3_CPP20_FLAG}}")
-    seqan3_config_print ("C++ Standard-20 support:    via ${SEQAN3_FEATURE_CPP20_FLAG_${SEQAN3_CPP20_FLAG}}")
-else ()
-    seqan3_config_error ("SeqAn3 requires C++20, but your compiler does not support it.")
-endif ()
-
 # ----------------------------------------------------------------------------
 # thread support (pthread, windows threads)
 # ----------------------------------------------------------------------------
@@ -394,10 +353,12 @@ file (WRITE "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/src.cxx" "${CX
 try_compile (SEQAN3_PLATFORM_TEST #
              ${CMAKE_BINARY_DIR}
              ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/src.cxx
-             CMAKE_FLAGS "-DCOMPILE_DEFINITIONS:STRING=${CMAKE_CXX_FLAGS} ${SEQAN3_CXX_FLAGS}"
-                         "-DINCLUDE_DIRECTORIES:STRING=${CMAKE_INCLUDE_PATH};${SEQAN3_INCLUDE_DIR};${SEQAN3_DEPENDENCY_INCLUDE_DIRS}"
+             CMAKE_FLAGS "-DINCLUDE_DIRECTORIES:STRING=${CMAKE_INCLUDE_PATH};${SEQAN3_INCLUDE_DIR};${SEQAN3_DEPENDENCY_INCLUDE_DIRS}"
              COMPILE_DEFINITIONS ${SEQAN3_DEFINITIONS}
              LINK_LIBRARIES ${SEQAN3_LIBRARIES}
+             CXX_STANDARD 23
+             CXX_STANDARD_REQUIRED ON
+             CXX_EXTENSIONS OFF
              OUTPUT_VARIABLE SEQAN3_PLATFORM_TEST_OUTPUT)
 
 if (SEQAN3_PLATFORM_TEST)
@@ -438,11 +399,9 @@ set (SEQAN3_INCLUDE_DIRS ${SEQAN3_INCLUDE_DIR} ${SEQAN3_DEPENDENCY_INCLUDE_DIRS}
 # ----------------------------------------------------------------------------
 
 if (SEQAN3_FOUND AND NOT TARGET seqan3::seqan3)
-    separate_arguments (SEQAN3_CXX_FLAGS_LIST UNIX_COMMAND "${SEQAN3_CXX_FLAGS}")
-
     add_library (seqan3_seqan3 INTERFACE)
     target_compile_definitions (seqan3_seqan3 INTERFACE ${SEQAN3_DEFINITIONS})
-    target_compile_options (seqan3_seqan3 INTERFACE ${SEQAN3_CXX_FLAGS_LIST})
+    target_compile_features(seqan3_seqan3 INTERFACE cxx_std_23)
     target_link_libraries (seqan3_seqan3 INTERFACE "${SEQAN3_LIBRARIES}")
     # include seqan3/include/ as -I, because seqan3 should never produce warnings.
     target_include_directories (seqan3_seqan3 INTERFACE "${SEQAN3_INCLUDE_DIR}")
@@ -469,7 +428,6 @@ if (SEQAN3_FIND_DEBUG)
     message ("  SEQAN3_INCLUDE_DIRS         ${SEQAN3_INCLUDE_DIRS}")
     message ("  SEQAN3_LIBRARIES            ${SEQAN3_LIBRARIES}")
     message ("  SEQAN3_DEFINITIONS          ${SEQAN3_DEFINITIONS}")
-    message ("  SEQAN3_CXX_FLAGS            ${SEQAN3_CXX_FLAGS}")
     message ("")
     message ("  SEQAN3_VERSION              ${SEQAN3_VERSION}")
     message ("  SEQAN3_VERSION_MAJOR        ${SEQAN3_VERSION_MAJOR}")

include/seqan3/argument_parser/validators.hpp

@@ -11,6 +11,7 @@
 
 #include <algorithm>
 #include <concepts>
+#include <exception>
 #include <filesystem>
 #include <fstream>
 #include <ranges>

include/seqan3/core/platform.hpp

@@ -104,8 +104,8 @@
 
 // C++ standard [required]
 #ifdef __cplusplus
-#    if (__cplusplus < 202002L)
-#        error "SeqAn3 requires C++20, make sure that you have set -std=c++20."
+#    if (__cplusplus < 202100)
+#        error "SeqAn3 requires C++23, make sure that you have set -std=c++23."
 #    endif
 #else
 #    error "This is not a C++ compiler."

include/seqan3/io/stream/detail/fast_ostreambuf_iterator.hpp

@@ -11,6 +11,7 @@
 #pragma once
 
 #include <algorithm>
+#include <array>
 #include <cassert>
 #include <iterator>
 #include <ranges>

test/seqan3-test.cmake

@@ -8,6 +8,18 @@
 
 cmake_minimum_required (VERSION 3.10...3.30)
 
+if (NOT DEFINED CMAKE_CXX_STANDARD)
+    set (CMAKE_CXX_STANDARD 23)
+endif ()
+
+if (NOT DEFINED CMAKE_CXX_STANDARD_REQUIRED)
+    set (CMAKE_CXX_STANDARD_REQUIRED OFF)
+endif ()
+
+if (NOT DEFINED CMAKE_CXX_EXTENSIONS)
+    set (CMAKE_CXX_EXTENSIONS OFF)
+endif ()
+
 # require SeqAn3 package
 find_package (SeqAn3 REQUIRED HINTS ${CMAKE_CURRENT_LIST_DIR}/../cmake)