Require C++11 and pass -std=c++11
This commit updates the Autotools build to require a C++11 compiler and
explicitly pass -std=c++11. This seems to be necessary for enabling
C++11 support in older compilers.
diff --git a/configure.ac b/configure.ac
index 7a5e3ab..634c0a6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -88,7 +88,7 @@
# Protocol Buffers contains several checks that are intended to be used only
# for debugging and which might hurt performance. Most users are probably
# end users who don't want these checks, so add -DNDEBUG by default.
- CXXFLAGS="$CXXFLAGS -DNDEBUG"
+ CXXFLAGS="$CXXFLAGS -std=c++11 -DNDEBUG"
AC_MSG_RESULT([use default: $PROTOBUF_OPT_FLAG $CXXFLAGS])
],[
@@ -207,7 +207,7 @@
esac
AM_CONDITIONAL([OBJC_CONFORMANCE_TEST], [test $OBJC_CONFORMANCE_TEST = 1])
-AX_CXX_COMPILE_STDCXX([11], [noext], [optional])
+AX_CXX_COMPILE_STDCXX([11], [noext], [mandatory])
# HACK: Make gmock's configure script pick up our copy of CFLAGS and CXXFLAGS,
# since the flags added by ACX_CHECK_SUNCC must be used when compiling gmock
