/* Copyright 2006-2008 Joaquin M Lopez Munoz. | |
* 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) | |
* | |
* See http://www.boost.org/libs/flyweight for library home page. | |
*/ | |
#ifndef BOOST_FLYWEIGHT_TAG_HPP | |
#define BOOST_FLYWEIGHT_TAG_HPP | |
#if defined(_MSC_VER)&&(_MSC_VER>=1200) | |
#pragma once | |
#endif | |
#include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */ | |
#include <boost/parameter/parameters.hpp> | |
#include <boost/type_traits/is_base_and_derived.hpp> | |
/* A type T can be used as a tag in the specification of a flyweight | |
* by passing it wrapped in the form tag<T>. | |
*/ | |
namespace boost{ | |
namespace flyweights{ | |
namespace detail{ | |
struct tag_marker{}; | |
template<typename T> | |
struct is_tag:is_base_and_derived<tag_marker,T> | |
{}; | |
} /* namespace flyweights::detail */ | |
template<typename T=parameter::void_> | |
struct tag:parameter::template_keyword<tag<>,T>,detail::tag_marker | |
{}; | |
} /* namespace flyweights */ | |
} /* namespace boost */ | |
#endif |