| // 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_DETAIL_IS_PLACEHOLDER_HPP_INCLUDED |
| #define BOOST_TYPE_ERASURE_DETAIL_IS_PLACEHOLDER_HPP_INCLUDED |
| |
| #include <boost/mpl/bool.hpp> |
| #include <boost/type_traits/is_base_and_derived.hpp> |
| #include <boost/type_erasure/placeholder.hpp> |
| |
| namespace boost { |
| |
| /** INTERNAL ONLY */ |
| struct use_default; |
| |
| namespace type_erasure { |
| |
| /** A metafunction that indicates whether a type is a @ref placeholder. */ |
| template<class T> |
| struct is_placeholder : ::boost::is_base_and_derived<placeholder, T> {}; |
| |
| /** INTERNAL ONLY */ |
| template<> |
| struct is_placeholder< ::boost::use_default> : ::boost::mpl::false_ {}; |
| |
| } |
| } |
| |
| #endif |
