$OpenBSD: patch-build_main_mk,v 1.2 2017/08/03 08:35:06 bentley Exp $
--- build/main.mk.orig	Sat May  6 21:02:40 2017
+++ build/main.mk	Sat May  6 21:02:52 2017
@@ -374,6 +374,8 @@ else
   else
     $(warning Unsupported compiler: $(CXX), please update Makefile)
   endif
+  # Enable C++11
+  COMPILE_FLAGS+=-std=c++11
 endif
 endif
 
