graph/include/boost/graph/overloading.hpp
Jeremiah Willcock cef7692b91 Merged more changes from Parallel BGL
[SVN r52116]
2009-04-01 18:07:00 +00:00

47 lines
1.5 KiB
C++

// Copyright 2004 The Trustees of Indiana University.
// Use, modification and distribution is subject to 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)
// Authors: Douglas Gregor
// Andrew Lumsdaine
//
// This file contains helps that enable concept-based overloading
// within the Boost Graph Library.
//
#ifndef BOOST_GRAPH_OVERLOADING_HPP
#define BOOST_GRAPH_OVERLOADING_HPP
#include <boost/type_traits/is_base_and_derived.hpp>
#include <boost/utility/enable_if.hpp>
namespace boost { namespace graph { namespace detail {
struct no_parameter {};
} } } // end namespace boost::graph::detail
#ifndef BOOST_NO_SFINAE
#define BOOST_GRAPH_ENABLE_IF_MODELS(Graph, Tag, Type) \
typename enable_if_c<(is_base_and_derived< \
Tag, \
typename graph_traits<Graph>::traversal_category>::value), \
Type>::type
#define BOOST_GRAPH_ENABLE_IF_MODELS_PARM(Graph, Tag) \
, BOOST_GRAPH_ENABLE_IF_MODELS(Graph, Tag, \
::boost::graph::detail::no_parameter) \
= ::boost::graph::detail::no_parameter()
#else
#define BOOST_GRAPH_ENABLE_IF_MODELS(Graph, Tag, Type) Type
#define BOOST_GRAPH_ENABLE_IF_MODELS_PARM(Graph, Tag)
#endif // no SFINAE support
#endif // BOOST_GRAPH_OVERLOADING_HPP