[boost] any_cast improvement

From: Unai Uribarri Rodríguez (unaiur_at_[hidden])
Date: 2003-01-15 16:17:51

any_cast, as is implemented in boost 1.29, has one weakness; it doesn't 
allow to compile this piece of code:

   any x=int(5);
   ++any_cast<int&>(x);

because any_cast tries to instanciate a pointer to int&. The attached 
patch solved this problem using boost::remove_reference from 
boost/type_traits.hpp.

any_cast<T&>(x) will return a reference to value contained in x if its 
type is T, or raise bad_cast otherwise.