I read your blog post and I'm afraid I don't see the point: you write some code to tap into a pre-existing library that figures out what platform you are on so that you can write out a 'config.h' that #define's the platform you are on so that you can then use the C preprocessor to pick a particular code path via conditional compilation.  Why go to all that bother?  Why not just write code that writes out the path you want to take and link against it?

        - Dan C.