boost/function_types/property_tags.hpp

   1
   2 // (C) Copyright Tobias Schwinger
   3 //
   4 // Use modification and distribution are subject to the boost Software License,
   5 // Version 1.0. (See http://www.boost.org/LICENSE_1_0.txt).
   6
   7 //------------------------------------------------------------------------------
   8
   9 #ifndef BOOST_FT_DETAIL_TAGS_HPP_INCLUDED
  10 #define BOOST_FT_DETAIL_TAGS_HPP_INCLUDED
  11
  12 #include <cstddef>
  13
  14 #include <boost/type_traits/integral_constant.hpp>
  15 #include <boost/mpl/bitxor.hpp>
  16
  17
  18 namespace boost { namespace function_types {
  19
  20 namespace detail
  21 {
  22   typedef long bits_t;
  23
  24   template<bits_t Value> struct constant
  25     : boost::integral_constant<bits_t,Value>
  26   { };
  27
  28   template<bits_t Bits, bits_t Mask> struct property_tag
  29   {
  30     typedef constant<Bits> bits;
  31     typedef constant<Mask> mask;
  32   };
  33
  34   template<typename T> struct bits : T::bits { };
  35   template<typename T> struct mask : T::mask { };
  36
  37   // forward declaration, defined in pp_tags
  38   template<bits_t Bits, bits_t CCID> struct encode_bits_impl;
  39
  40   // forward declaration, defined in pp_tags
  41   template<bits_t LHS_bits, bits_t LHS_mask,
  42            bits_t RHS_bits, bits_t RHS_mask>
  43   struct tag_ice;
  44
  45   // forward declaration, defined in retag_default_cc
  46   template<class Tag, class RegTag = Tag> struct retag_default_cc;
  47
  48   template<bits_t Bits, bits_t CCID> struct encode_bits
  49     : constant<
  50         ::boost::function_types::detail::encode_bits_impl<Bits,CCID>::value
  51       >
  52   { };
  53
  54   template<class LHS, class RHS> struct compound_tag
  55   {
  56     typedef constant<
  57       ::boost::function_types::detail::tag_ice
  58         < ::boost::function_types::detail::bits<LHS>::value
  59         , ::boost::function_types::detail::mask<LHS>::value
  60         , ::boost::function_types::detail::bits<RHS>::value
  61         , ::boost::function_types::detail::mask<RHS>::value
  62         >::combined_bits
  63     > bits;
  64
  65     typedef constant<
  66       ::boost::function_types::detail::tag_ice
  67         < ::boost::function_types::detail::bits<LHS>::value
  68         , ::boost::function_types::detail::mask<LHS>::value
  69         , ::boost::function_types::detail::bits<RHS>::value
  70         , ::boost::function_types::detail::mask<RHS>::value
  71         >::combined_mask
  72     > mask;
  73   };
  74
  75   template <class Base, class PropOld, class PropNew>
  76   struct changed_tag
  77     : Base
  78   {
  79     typedef mpl::bitxor_
  80         <typename Base::bits, typename PropOld::bits, typename PropNew::bits>
  81     bits;
  82   };
  83
  84   template<class Tag, class QueryTag> struct represents_impl
  85     : boost::integral_constant<bool,
  86         ::boost::function_types::detail::tag_ice
  87           < ::boost::function_types::detail::bits<Tag>::value
  88           , ::boost::function_types::detail::mask<Tag>::value
  89           , ::boost::function_types::detail::bits<QueryTag>::value
  90           , ::boost::function_types::detail::mask<QueryTag>::value
  91           >::match
  92       >
  93   { };
  94
  95 } // namespace detail
  96
  97 typedef detail::property_tag<0,0> null_tag;
  98
  99 template<class Tag1, class Tag2, class Tag3 = null_tag, class Tag4 = null_tag>
 100 struct tag
 101   : detail::compound_tag< detail::compound_tag<Tag1,Tag2>,
 102         detail::compound_tag<Tag3,Tag4> >
 103 { };
 104
 105 #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
 106 template<class Tag1, class Tag2, class Tag3> struct tag<Tag1,Tag2,Tag3,null_tag>
 107   : detail::compound_tag<detail::compound_tag<Tag1,Tag2>,Tag3>
 108 { };
 109 template<class Tag1, class Tag2> struct tag<Tag1,Tag2,null_tag,null_tag>
 110   : detail::compound_tag<Tag1,Tag2>
 111 { };
 112 template<class Tag1> struct tag<Tag1,null_tag,null_tag,null_tag>
 113   : Tag1
 114 { };
 115 #endif
 116
 117
 118 template<class Tag, class QueryTag> struct represents
 119   : detail::represents_impl<Tag, detail::retag_default_cc<QueryTag,Tag> >
 120 { };
 121
 122
 123 template<class Tag, class QueryTag> struct extract
 124 {
 125   typedef detail::constant<
 126     ::boost::function_types::detail::tag_ice
 127       < ::boost::function_types::detail::bits<Tag>::value
 128       , ::boost::function_types::detail::mask<Tag>::value
 129       , ::boost::function_types::detail::bits<QueryTag>::value
 130       , ::boost::function_types::detail::mask<QueryTag>::value
 131       >::extracted_bits
 132   > bits;
 133
 134   typedef detail::constant<
 135     ::boost::function_types::detail::mask<QueryTag>::value
 136   > mask;
 137 };
 138
 139 } } // namespace ::boost::function_types
 140
 141 #include <boost/function_types/detail/pp_tags/preprocessed.hpp>
 142
 143 namespace boost { namespace function_types {
 144 #define BOOST_FT_cc_file <boost/function_types/detail/pp_tags/cc_tag.hpp>
 145 #include <boost/function_types/detail/pp_loop.hpp>
 146 } } // namespace boost::function_types
 147
 148 #endif
 149