boost/type_erasure/detail/check_map.hpp

   1 // Boost.TypeErasure library
   2 //
   3 // Copyright 2012 Steven Watanabe
   4 //
   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)
   8 //
   9 // $Id$
  10
  11 #ifndef BOOST_TYPE_ERASURE_DETAIL_CHECK_MAP_HPP_INCLUDED
  12 #define BOOST_TYPE_ERASURE_DETAIL_CHECK_MAP_HPP_INCLUDED
  13
  14 #include <boost/mpl/not.hpp>
  15 #include <boost/mpl/or.hpp>
  16 #include <boost/mpl/bool.hpp>
  17 #include <boost/mpl/set.hpp>
  18 #include <boost/mpl/has_key.hpp>
  19 #include <boost/mpl/find_if.hpp>
  20 #include <boost/mpl/end.hpp>
  21 #include <boost/type_traits/is_same.hpp>
  22 #include <boost/type_erasure/detail/get_placeholders.hpp>
  23 #include <boost/type_erasure/deduced.hpp>
  24 #include <boost/type_erasure/static_binding.hpp>
  25
  26 namespace boost {
  27 namespace type_erasure {
  28 namespace detail {
  29
  30 template<class T>
  31 struct is_deduced : boost::mpl::false_ {};
  32 template<class T>
  33 struct is_deduced< ::boost::type_erasure::deduced<T> > : boost::mpl::true_ {};
  34
  35 // returns true if Map has a key for every non-deduced placeholder in Concept
  36 template<class Concept, class Map>
  37 struct check_map {
  38     typedef typename normalize_concept<Concept>::basic basic_components;
  39
  40     // Every non-deduced placeholder referenced in this
  41     // map is indirectly deduced.
  42     typedef typename ::boost::type_erasure::detail::get_placeholder_normalization_map<
  43         Concept>::type placeholder_subs;
  44     typedef typename ::boost::mpl::fold<
  45         placeholder_subs,
  46         ::boost::mpl::set0<>,
  47         ::boost::mpl::insert<
  48             ::boost::mpl::_1,
  49             ::boost::mpl::second< ::boost::mpl::_2>
  50         >
  51     >::type indirect_deduced_placeholders;
  52
  53     typedef typename ::boost::mpl::fold<
  54         basic_components,
  55         ::boost::mpl::set0<>,
  56         ::boost::type_erasure::detail::get_placeholders<
  57             ::boost::mpl::_2,
  58             ::boost::mpl::_1
  59         >
  60     >::type placeholders;
  61     typedef typename ::boost::is_same<
  62         typename ::boost::mpl::find_if<
  63             placeholders,
  64             ::boost::mpl::not_<
  65                 ::boost::mpl::or_<
  66                     ::boost::type_erasure::detail::is_deduced< ::boost::mpl::_1>,
  67                     ::boost::mpl::has_key<Map, ::boost::mpl::_1>,
  68                     ::boost::mpl::has_key<indirect_deduced_placeholders, ::boost::mpl::_1>
  69                 >
  70             >
  71         >::type,
  72         typename ::boost::mpl::end<placeholders>::type
  73     >::type type;
  74 };
  75
  76 template<class Concept, class Map>
  77 struct check_map<Concept, ::boost::type_erasure::static_binding<Map> > :
  78     check_map<Concept, Map>
  79 {};
  80
  81 }
  82 }
  83 }
  84
  85 #endif