[boost] [type_erasure] move

Hi Steven, I'm looking for a crash I get in my own code with g++4.8.1 (4.5 - 4.7 are ok). Maybe you can help me: - there is a copy_constructible concept, but no moveable. Is it enough to add one on the same model? It looks like you std::forward so I'd say yes. Correct? template<class T = _self> struct move_constructible : ::boost::mpl::vector<constructible<T(T&&)>, destructible<T> > {}; - If I std::move a copy_constructible any type by accident, what do I get? A copy? A crash? Thanks, Christophe