autotools c++11

Makefile.am

 ## Process this file with automake to produce Makefile.in
+AM_CXXFLAGS = -std=gnu++11
+
 ACLOCAL_AMFLAGS = -I m4
 
 AUTOMAKE_OPTIONS = foreign

ci/build-linux-autotools.sh

@@ -39,6 +39,6 @@ autoreconf -i
 # Run in a subdirectory to keep the sources clean
 mkdir build || true
 cd build
-../configure CXX="-std=c++11"
+../configure
 
 make -j {NPROCESSORS:-2}