boost/type_erasure/is_subconcept.hpp
// Boost.TypeErasure library
//
// Copyright 2012 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_IS_SUBCONCEPT_HPP_INCLUDED
#define BOOST_TYPE_ERASURE_IS_SUBCONCEPT_HPP_INCLUDED
#include <boost/mpl/bool.hpp>
#include <boost/mpl/not.hpp>
#include <boost/mpl/if.hpp>
#include <boost/mpl/end.hpp>
#include <boost/mpl/find_if.hpp>
#include <boost/mpl/has_key.hpp>
#include <boost/type_traits/is_same.hpp>
#include <boost/type_erasure/detail/normalize.hpp>
#include <boost/type_erasure/detail/rebind_placeholders.hpp>
#include <boost/type_erasure/static_binding.hpp>
namespace boost {
namespace type_erasure {
namespace detail {
template<class Sub, class Super, class PlaceholderMap>
struct is_subconcept_impl {
typedef typename ::boost::type_erasure::detail::normalize_concept<
Super>::concept_set super_set;
typedef typename ::boost::type_erasure::detail::get_placeholder_normalization_map<
Super
>::type placeholder_subs_super;
typedef typename ::boost::type_erasure::detail::normalize_concept<
Sub>::type normalized_sub;
typedef typename ::boost::type_erasure::detail::get_placeholder_normalization_map<
Sub
>::type placeholder_subs_sub;
typedef typename ::boost::mpl::eval_if< ::boost::is_same<PlaceholderMap, void>,
boost::mpl::identity<void>,
::boost::type_erasure::detail::convert_deductions<
PlaceholderMap,
placeholder_subs_sub,
placeholder_subs_super
>
>::type bindings;
typedef typename ::boost::mpl::if_< ::boost::is_same<PlaceholderMap, void>,
::boost::mpl::_1,
::boost::type_erasure::detail::rebind_placeholders<
::boost::mpl::_1,
bindings
>
>::type transform;
typedef typename ::boost::is_same<
typename ::boost::mpl::find_if<normalized_sub,
::boost::mpl::not_<
::boost::mpl::has_key<
super_set,
transform
>
>
>::type,
typename ::boost::mpl::end<normalized_sub>::type
>::type type;
};
}
/**
* @ref is_subconcept is a boolean metafunction that determines whether
* one concept is a sub-concept of another.
*
* \code
* is_subconcept<incrementable<>, incrementable<> > -> true
* is_subconcept<incrementable<>, addable<> > -> false
* is_subconcept<incrementable<_a>, forward_iterator<_iter>,
* mpl::map<mpl::pair<_a, _iter> > > -> true
* \endcode
*
* \tparam Sub The sub concept
* \tparam Super The super concept
* \tparam PlaceholderMap (optional) An MPL map with keys for
* every non-deduced placeholder in Sub. The
* associated value of each key is the corresponding placeholder
* in Super. If @c PlaceholderMap is omitted, @c Super and @c Sub
* are presumed to use the same set of placeholders.
*/
template<class Sub, class Super, class PlaceholderMap = void>
struct is_subconcept : ::boost::type_erasure::detail::is_subconcept_impl<Sub, Super, PlaceholderMap>::type {
};
#ifndef BOOST_TYPE_ERASURE_DOXYGEN
template<class Sub, class Super, class PlaceholderMap>
struct is_subconcept<Sub, Super, static_binding<PlaceholderMap> > :
::boost::type_erasure::detail::is_subconcept_impl<Sub, Super, PlaceholderMap>::type
{};
#endif
}
}
#endif