1# Check if $CXX does or can be made to support C++11 by adding switches.
2# If $CXX explicitly selects a language standard, then
3# refrain from overriding this choice.
4AC_DEFUN([AX_CXX_COMPILE_STDCXX_11_NO_OVERRIDE], [dnl
5	AC_PROG_GREP
6	echo $CXX | $GREP -e "-std=" > /dev/null 2> /dev/null
7	if test $? -eq 0; then
8		_AX_CXX_COMPILE_STDCXX_11_DEFAULT
9	else
10		AX_CXX_COMPILE_STDCXX_11([noext], [optional])
11	fi
12])
13
14# Check if $CXX supports C++11 by default (without adding switches).
15# This is a trimmed down version of AX_CXX_COMPILE_STDCXX_11
16# that reuses its _AX_CXX_COMPILE_STDCXX_testbody_11.
17AC_DEFUN([_AX_CXX_COMPILE_STDCXX_11_DEFAULT], [dnl
18  AC_LANG_PUSH([C++])dnl
19  ac_success=no
20  AC_CACHE_CHECK(whether $CXX supports C++11 features by default,
21  ax_cv_cxx_compile_cxx11,
22  [AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_testbody_11])],
23    [ax_cv_cxx_compile_cxx11=yes],
24    [ax_cv_cxx_compile_cxx11=no])])
25  if test x$ax_cv_cxx_compile_cxx11 = xyes; then
26    ac_success=yes
27  fi
28  AC_LANG_POP([C++])
29  if test x$ac_success = xno; then
30    HAVE_CXX11=0
31  else
32    HAVE_CXX11=1
33    AC_DEFINE(HAVE_CXX11,1,
34              [define if the compiler supports basic C++11 syntax])
35  fi
36  AC_SUBST(HAVE_CXX11)
37])
38