mkmf

How to add a C++ compiler flag to extconf.rb

I'm writing a Ruby extension, for which I have a standard mkmf configuration script, but I need to add a special include flag (--std=c++0x) to all of the C++ compilation steps. I don't want it in the C compilation steps, 'cause it throws warnings. How should I do this? require 'mkmf' create_makefile('thing') For instance, I tried $CXX...