Update configure.ac

configure.ac

@@ -16,7 +16,7 @@ AC_LANG([C++])
 
 # Checks for programs.
 AX_PROG_CXX_MPI(,[CXX=$MPICXX],[])
-AX_MPI([CXX=$MPICXX; CC=$MPICXX; CFLAGS=$CXXFLAGS],
+AX_MPI([CXX=$MPICXX; CC=$MPICC; CFLAGS=$CFLAGS],
        [AC_MSG_ERROR([Cannot find mpicxx. Make sure that MPI is installed and location of compiler is in PATH.])])
 AX_COMPILER_VENDOR
 AC_PROG_AWK

m4/ax_cxx_def_template_arg.m4

@@ -17,6 +17,7 @@ m4_define([_AX_CXX_DEF_TEMPLATE_ARG_testbody], [[
 AC_DEFUN([AX_CXX_DEF_TEMPLATE_ARG], [dnl
 
   AC_LANG_PUSH([C++])dnl
+  AC_LANG_WERROR([on])
   ac_success=no
   AC_CACHE_CHECK(whether $CXX supports default template arguments by default,
   ax_cv_cxx_compile_template,
@@ -46,6 +47,7 @@ AC_DEFUN([AX_CXX_DEF_TEMPLATE_ARG], [dnl
     done
   fi
 
+  AC_LANG_WERROR([on])
   AC_LANG_POP([C++])
   if test x$ac_success = xno; then
     AC_MSG_ERROR([*** Compiler does not support default template arguments in function templates.