try to use c++14 mode as c++17 introduces std::byte which breaks CryptoPP 5.x

HinTak · HinTak · commit d9394aaf3dd4 · 2021-05-06T01:51:24.000+01:00
diff --git a/config/configure.in b/config/configure.in
@@ -1177,7 +1177,8 @@ echo "--------------------------------------"
 	  DONKEY_SUI=no
 	else
 	  AC_MSG_RESULT(yes)
-	  ACX_CHECK_CXX_FLAGS(-fno-omit-frame-pointer,cv_no_omit_frame_pointer, CRYPTOPPFLAGS="-fno-omit-frame-pointer")
+	  ACX_CHECK_CXX_FLAGS(-std=c++14,cv_stdcxx14, CRYPTOPPFLAGS="-std=c++14")
+	  ACX_CHECK_CXX_FLAGS(-fno-omit-frame-pointer,cv_no_omit_frame_pointer, CRYPTOPPFLAGS="$CRYPTOPPFLAGS -fno-omit-frame-pointer")
 	  ACX_CHECK_CXX_FLAGS(-mno-omit-leaf-frame-pointer,cv_no_omit_leaf_frame_pointer, CRYPTOPPFLAGS="$CRYPTOPPFLAGS -mno-omit-leaf-frame-pointer")
 	  CXX=$NEWCXX
 	  CXX_VERSION=`$CXX -dumpversion`
