# File lib/phusion_passenger/platform_info/compiler.rb, line 459
        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 =~ /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