From 7af6cbe74d48a9853b60b029d4ce38a963386138 Mon Sep 17 00:00:00 2001
From: Romain Naour <romain.naour@gmail.com>
Date: Sun, 3 Jul 2016 20:19:48 +0200
Subject: [PATCH] webrtc: C++11 is only required for WebRTC support

Make C++11 support optional and explicitely check for gnu++11.

Stop the build only if no C++11 support has been found and WebRTC
support has been resquested.

Signed-off-by: Romain Naour <romain.naour@gmail.com>
---
 configure.ac | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 4edc8e0..fea93a9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -84,7 +84,7 @@ AM_PROG_CC_C_O
 # Only required if you want the WebRTC canceller -- no runtime dep on
 # libstdc++ otherwise
 AC_PROG_CXX
-AX_CXX_COMPILE_STDCXX_11
+AX_CXX_COMPILE_STDCXX_11([ext],[optional])
 AC_PROG_GCC_TRADITIONAL
 AC_USE_SYSTEM_EXTENSIONS
 
@@ -1414,6 +1414,9 @@ fi
 AC_ARG_ENABLE([webrtc-aec],
     AS_HELP_STRING([--enable-webrtc-aec], [Enable the optional WebRTC-based echo canceller]))
 
+AS_IF([test "x$enable_webrtc_aec" = "xyes" && test "$HAVE_CXX11" = "0"],
+    [AC_MSG_ERROR([*** webrtc-audio-processing needs C++11 support])])
+
 AS_IF([test "x$enable_webrtc_aec" != "xno"],
     [PKG_CHECK_MODULES(WEBRTC, [ webrtc-audio-processing >= 0.2 ], [HAVE_WEBRTC=1], [HAVE_WEBRTC=0])],
     [HAVE_WEBRTC=0])
-- 
2.5.5