Fix for travis

Author: deltaoscarmike

.travis.yml

@@ -34,6 +34,7 @@ matrix:
             - libglew-dev
             - libftgl-dev
             - libglm-dev
+            - libc++-dev
       env:
         - MATRIX_EVAL="CC=clang-5.0 && CXX=clang++-5.0"
     # linux/gcc
@@ -48,6 +49,7 @@ matrix:
             - libglew-dev
             - libftgl-dev
             - libglm-dev
+            - libc++-dev
       env:
         - MATRIX_EVAL="CC=gcc-7 && CXX=g++-7"
 

configure.ac

@@ -76,11 +76,11 @@ AC_PREFIX_DEFAULT([/usr/local])
 
 AC_PROG_MKDIR_P
 
-AX_CHECK_COMPILE_FLAG([-stdlib=libstdc++], [
-                        CXXFLAGS="$CXXFLAGS -stdlib=libstdc++"])
+AX_CHECK_COMPILE_FLAG([-stdlib=libc++], [
+                        CXXFLAGS="$CXXFLAGS -stdlib=libc++"])
 
-AX_CHECK_COMPILE_FLAG([-std=c++14], [
-                        CXXFLAGS="$CXXFLAGS -std=c++14"])
+AX_CHECK_COMPILE_FLAG([-std=c++11], [
+                        CXXFLAGS="$CXXFLAGS -std=c++11"])
 
 dnl Qt
 AC_ARG_ENABLE([qt],