Is there a Type2Type in boost ?

Hi everyone, I've looked around and failed to find the Type2Type template, detailed by Andrei Alexandrescu in a CUJ article (http://cuj.com/experts/1810/alexandr.htm?topic=experts), in boost. While the implementation is trivial: template<typename Type> struct Type2Type { typedef Type original_type; }; I'd rather have it in a well known library. Has it been replaced by something else ? Baptiste.