Merge pull request #42 from canhld94/fix_odr

Fix ODR

Author: rschu1ze

boost/phoenix/stl/tuple.hpp

@@ -109,8 +109,8 @@ namespace boost { namespace phoenix {
     // Make unpacked argument placeholders
     namespace placeholders {
         #define BOOST_PP_LOCAL_LIMITS (1, BOOST_PHOENIX_ARG_LIMIT)
-        #define BOOST_PP_LOCAL_MACRO(N)                                                \
-            auto uarg##N =                                                             \
+        #define BOOST_PP_LOCAL_MACRO(N)                                                 \
+            const auto uarg##N =                                                        \
             boost::phoenix::get_<(N)-1>(boost::phoenix::placeholders::arg1);
         #include BOOST_PP_LOCAL_ITERATE()
     }