[libxml++] Require C++11

[Kjell Ahlstedt <kjellahl src gnome org>]

commit 2f0ecc3d5db8951f68fa6f9b6fd18a28bbd7f242
Author: Kjell Ahlstedt <kjell ahlstedt bredband net>
Date:   Sun Jul 19 14:43:57 2015 +0200

    Require C++11
    
    * configure.ac: Use MM_AX_CXX_COMPILE_STDCXX_11 from mm-common to check for
    compiler support for C++11 and use it (-std=c++11 for current versions of g++).
    Among other reasons, this is because libsigc++ and glibmm now require C++11,
    and gmmproc generates C++11 code.

 configure.ac |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 0afd0cc..b59eec0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -13,7 +13,7 @@ m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES])
 AM_MAINTAINER_MODE([disable])
 AC_ARG_VAR([ACLOCAL_FLAGS], [aclocal flags, e.g. -I <macro dir>])
 
-MM_PREREQ([0.9.7])
+MM_PREREQ([0.9.8])
 MM_INIT_MODULE([libxml++-2.6])
 
 # Copy the mm-common .pl scripts into docs/,
@@ -25,6 +25,8 @@ MM_CONFIG_DOCTOOL_DIR([docs])
 AC_SUBST([LIBXMLXX_SO_VERSION], [2:7:0])
 
 AC_PROG_CXX
+MM_AX_CXX_COMPILE_STDCXX_11([noext],[mandatory])
+
 LT_PREREQ([2.2.6])
 LT_INIT([dlopen win32-dll disable-static])