# File src/ruby_supportlib/phusion_passenger/platform_info/compiler.rb, line 455
    def self.cxx_11_flag
      # C++11 support on FreeBSD 10.0 + Clang seems to be bugged.
      # http://llvm.org/bugs/show_bug.cgi?id=18310
      return nil if os_name_simple == "freebsd"

      source = %{
        struct Foo {
          Foo(Foo &&f) { }
        };
      }
      if try_compile("Checking for C++ -std=gnu++11 compiler flag", :cxx, source, '-std=gnu++11')
        return "-std=gnu++11"
      elsif try_compile("Checking for C++ -std=c++11 compiler flag", :cxx, source, '-std=c++11')
        return "-std=c++11"
      else
        return nil
      end
    end