ceph/src/boost/libs/graph/include/boost/graph/overloading.hpp

   1 // Copyright 2004 The Trustees of Indiana University.
   2
   3 // Use, modification and distribution is subject to the Boost Software
   4 // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   5 // http://www.boost.org/LICENSE_1_0.txt)
   6
   7 //  Authors: Douglas Gregor
   8 //           Andrew Lumsdaine
   9
  10 //
  11 // This file contains helps that enable concept-based overloading
  12 // within the Boost Graph Library.
  13 //
  14 #ifndef BOOST_GRAPH_OVERLOADING_HPP
  15 #define BOOST_GRAPH_OVERLOADING_HPP
  16
  17 #include <boost/type_traits/is_base_and_derived.hpp>
  18 #include <boost/utility/enable_if.hpp>
  19
  20 namespace boost {  namespace graph { namespace detail {
  21
  22 struct no_parameter {};
  23
  24 } } } // end namespace boost::graph::detail
  25
  26 #ifndef BOOST_NO_SFINAE
  27
  28 #define BOOST_GRAPH_ENABLE_IF_MODELS(Graph, Tag, Type)               \
  29   typename enable_if_c<(is_base_and_derived<                         \
  30                           Tag,                                       \
  31                           typename graph_traits<Graph>::traversal_category>::value), \
  32                        Type>::type
  33
  34 #define BOOST_GRAPH_ENABLE_IF_MODELS_PARM(Graph, Tag)                   \
  35   , BOOST_GRAPH_ENABLE_IF_MODELS(Graph, Tag,                            \
  36                                  ::boost::graph::detail::no_parameter)  \
  37     = ::boost::graph::detail::no_parameter()
  38
  39 #else
  40
  41 #define BOOST_GRAPH_ENABLE_IF_MODELS(Graph, Tag, Type) Type
  42 #define BOOST_GRAPH_ENABLE_IF_MODELS_PARM(Graph, Tag)
  43
  44 #endif // no SFINAE support
  45
  46 #endif // BOOST_GRAPH_OVERLOADING_HPP