1 // Boost.TypeErasure library
3 // Copyright 2011 Steven Watanabe
5 // Distributed under the Boost Software License Version 1.0. (See
6 // accompanying file LICENSE_1_0.txt or copy at
7 // http://www.boost.org/LICENSE_1_0.txt)
11 #ifndef BOOST_TYPE_ERASURE_PLACEHOLDER_OF_HPP_INCLUDED
12 #define BOOST_TYPE_ERASURE_PLACEHOLDER_OF_HPP_INCLUDED
15 namespace type_erasure {
17 template<class Concept, class T>
20 template<class Concept, class T>
24 * A metafunction returning the (const/reference qualified) placeholder
25 * corresponding to an @ref any. It will also work for all bases
26 * of @ref any, so it can be applied to the @c Base
27 * parameter of @ref concept_interface.
32 #ifdef BOOST_TYPE_ERASURE_DOXYGEN
33 typedef detail::unspecified type;
35 typedef typename ::boost::type_erasure::placeholder_of<
36 typename T::_boost_type_erasure_derived_type
42 template<class Concept, class T>
43 struct placeholder_of< ::boost::type_erasure::any<Concept, T> >
49 template<class Concept, class T>
50 struct placeholder_of< ::boost::type_erasure::param<Concept, T> >