| // Boost.TypeErasure library |
| // |
| // Copyright 2011 Steven Watanabe |
| // |
| // Distributed under the Boost Software License Version 1.0. (See |
| // accompanying file LICENSE_1_0.txt or copy at |
| // http://www.boost.org/LICENSE_1_0.txt) |
| // |
| // $Id$ |
| |
| #ifndef BOOST_TYPE_ERASURE_REBIND_ANY_HPP_INCLUDED |
| #define BOOST_TYPE_ERASURE_REBIND_ANY_HPP_INCLUDED |
| |
| #include <boost/mpl/if.hpp> |
| #include <boost/type_traits/remove_cv.hpp> |
| #include <boost/type_traits/remove_reference.hpp> |
| #include <boost/type_erasure/is_placeholder.hpp> |
| #include <boost/type_erasure/concept_of.hpp> |
| |
| namespace boost { |
| namespace type_erasure { |
| |
| template<class Concept, class T> |
| class any; |
| |
| /** |
| * A metafunction that changes the @ref placeholder of |
| * an @ref any. If @c T is not a placeholder, |
| * returns @c T unchanged. This class is intended |
| * to be used in @ref concept_interface to deduce |
| * the argument types from the arguments of the concept. |
| * |
| * @pre Any must be a specialization of @ref any or a base |
| * class of such a specialization. |
| * |
| * \code |
| * rebind_any<any<Concept>, _a>::type -> any<Concept, _a> |
| * rebind_any<any<Concept>, _b&>::type -> any<Concept, _b&> |
| * rebind_any<any<Concept>, int>::type -> int |
| * \endcode |
| * |
| * @see derived, as_param |
| */ |
| template<class Any, class T> |
| struct rebind_any |
| { |
| #ifdef BOOST_TYPE_ERASURE_DOXYGEN |
| typedef detail::unspecified type; |
| #else |
| typedef typename ::boost::mpl::if_< |
| ::boost::type_erasure::is_placeholder< |
| typename ::boost::remove_cv< |
| typename ::boost::remove_reference<T>::type |
| >::type |
| >, |
| ::boost::type_erasure::any< |
| typename ::boost::type_erasure::concept_of<Any>::type, |
| T |
| >, |
| T |
| >::type type; |
| #endif |
| }; |
| |
| } |
| } |
| |
| #endif |