ceph/src/boost/libs/variant/include/boost/variant/detail/substitute.hpp

   1
   2 #if !defined(BOOST_PP_IS_ITERATING)
   3
   4 ///// header body
   5
   6 //-----------------------------------------------------------------------------
   7 // boost variant/detail/substitute.hpp header file
   8 // See http://www.boost.org for updates, documentation, and revision history.
   9 //-----------------------------------------------------------------------------
  10 //
  11 // Copyright (c) 2003
  12 // Eric Friedman
  13 //
  14 // Distributed under the Boost Software License, Version 1.0. (See
  15 // accompanying file LICENSE_1_0.txt or copy at
  16 // http://www.boost.org/LICENSE_1_0.txt)
  17
  18 #ifndef BOOST_VARIANT_DETAIL_SUBSTITUTE_HPP
  19 #define BOOST_VARIANT_DETAIL_SUBSTITUTE_HPP
  20
  21 #include <boost/mpl/aux_/config/ctps.hpp>
  22
  23 #include <boost/variant/detail/substitute_fwd.hpp>
  24 #include <boost/variant/variant_fwd.hpp> // for BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES
  25 #include <boost/mpl/aux_/lambda_arity_param.hpp>
  26 #include <boost/mpl/aux_/preprocessor/params.hpp>
  27 #include <boost/mpl/aux_/preprocessor/repeat.hpp>
  28 #include <boost/mpl/int_fwd.hpp>
  29 #include <boost/mpl/limits/arity.hpp>
  30 #include <boost/preprocessor/cat.hpp>
  31 #include <boost/preprocessor/empty.hpp>
  32 #include <boost/preprocessor/arithmetic/inc.hpp>
  33 #include <boost/preprocessor/iterate.hpp>
  34
  35 namespace boost {
  36 namespace detail { namespace variant {
  37
  38 #if !defined(BOOST_VARIANT_DETAIL_NO_SUBSTITUTE)
  39
  40 ///////////////////////////////////////////////////////////////////////////////
  41 // (detail) metafunction substitute
  42 //
  43 // Substitutes one type for another in the given type expression.
  44 //
  45
  46 //
  47 // primary template
  48 //
  49 template <
  50       typename T, typename Dest, typename Source
  51       BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(
  52           typename Arity /* = ... (see substitute_fwd.hpp) */
  53         )
  54     >
  55 struct substitute
  56 {
  57     typedef T type;
  58 };
  59
  60 //
  61 // tag substitution specializations
  62 //
  63
  64 #define BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL_SUBSTITUTE_TAG(CV_) \
  65     template <typename Dest, typename Source> \
  66     struct substitute< \
  67           CV_ Source \
  68         , Dest \
  69         , Source \
  70           BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(mpl::int_<-1>) \
  71         > \
  72     { \
  73         typedef CV_ Dest type; \
  74     }; \
  75     /**/
  76
  77 BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL_SUBSTITUTE_TAG( BOOST_PP_EMPTY() )
  78 BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL_SUBSTITUTE_TAG(const)
  79 BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL_SUBSTITUTE_TAG(volatile)
  80 BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL_SUBSTITUTE_TAG(const volatile)
  81
  82 #undef BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL_SUBSTITUTE_TAG
  83
  84 //
  85 // pointer specializations
  86 //
  87 #define BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL_HANDLE_POINTER(CV_) \
  88     template <typename T, typename Dest, typename Source> \
  89     struct substitute< \
  90           T * CV_ \
  91         , Dest \
  92         , Source \
  93           BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(mpl::int_<-1>) \
  94         > \
  95     { \
  96         typedef typename substitute< \
  97               T, Dest, Source \
  98             >::type * CV_ type; \
  99     }; \
 100     /**/
 101
 102 BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL_HANDLE_POINTER( BOOST_PP_EMPTY() )
 103 BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL_HANDLE_POINTER(const)
 104 BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL_HANDLE_POINTER(volatile)
 105 BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL_HANDLE_POINTER(const volatile)
 106
 107 #undef BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL_HANDLE_POINTER
 108
 109 //
 110 // reference specializations
 111 //
 112 template <typename T, typename Dest, typename Source>
 113 struct substitute<
 114       T&
 115     , Dest
 116     , Source
 117       BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(mpl::int_<-1>)
 118     >
 119 {
 120     typedef typename substitute<
 121           T, Dest, Source
 122         >::type & type;
 123 };
 124
 125 //
 126 // template expression (i.e., F<...>) specializations
 127 //
 128
 129 #if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
 130 template <
 131       template <typename...> class F
 132     , typename... Ts
 133     , typename Dest
 134     , typename Source
 135       BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(typename Arity)
 136     >
 137 struct substitute<
 138       F<Ts...>
 139     , Dest
 140     , Source
 141       BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(Arity)
 142     >
 143 {
 144     typedef F<typename substitute<
 145           Ts, Dest, Source
 146         >::type...> type;
 147 };
 148 #endif // !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
 149
 150 #define BOOST_VARIANT_AUX_SUBSTITUTE_TYPEDEF_IMPL(N) \
 151     typedef typename substitute< \
 152           BOOST_PP_CAT(U,N), Dest, Source \
 153         >::type BOOST_PP_CAT(u,N); \
 154     /**/
 155
 156 #define BOOST_VARIANT_AUX_SUBSTITUTE_TYPEDEF(z, N, _) \
 157     BOOST_VARIANT_AUX_SUBSTITUTE_TYPEDEF_IMPL( BOOST_PP_INC(N) ) \
 158     /**/
 159
 160 #define BOOST_PP_ITERATION_LIMITS (0,BOOST_MPL_LIMIT_METAFUNCTION_ARITY)
 161 #define BOOST_PP_FILENAME_1 <boost/variant/detail/substitute.hpp>
 162 #include BOOST_PP_ITERATE()
 163
 164 #undef BOOST_VARIANT_AUX_SUBSTITUTE_TYPEDEF_IMPL
 165 #undef BOOST_VARIANT_AUX_SUBSTITUTE_TYPEDEF
 166
 167 #endif // !defined(BOOST_VARIANT_DETAIL_NO_SUBSTITUTE)
 168
 169 }} // namespace detail::variant
 170 } // namespace boost
 171
 172 #endif // BOOST_VARIANT_DETAIL_SUBSTITUTE_HPP
 173
 174 ///// iteration, depth == 1
 175
 176 #elif BOOST_PP_ITERATION_DEPTH() == 1
 177 #define i BOOST_PP_FRAME_ITERATION(1)
 178
 179 #if i > 0
 180
 181 //
 182 // template specializations
 183 //
 184 template <
 185       template < BOOST_MPL_PP_PARAMS(i,typename P) > class T
 186     , BOOST_MPL_PP_PARAMS(i,typename U)
 187     , typename Dest
 188     , typename Source
 189     >
 190 struct substitute<
 191       T< BOOST_MPL_PP_PARAMS(i,U) >
 192     , Dest
 193     , Source
 194       BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(mpl::int_<( i )>)
 195     >
 196 {
 197 private:
 198     BOOST_MPL_PP_REPEAT(i, BOOST_VARIANT_AUX_SUBSTITUTE_TYPEDEF, _)
 199
 200 public:
 201     typedef T< BOOST_MPL_PP_PARAMS(i,u) > type;
 202 };
 203
 204 //
 205 // function specializations
 206 //
 207 template <
 208       typename R
 209     , BOOST_MPL_PP_PARAMS(i,typename U)
 210     , typename Dest
 211     , typename Source
 212     >
 213 struct substitute<
 214       R (*)( BOOST_MPL_PP_PARAMS(i,U) )
 215     , Dest
 216     , Source
 217       BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(mpl::int_<-1>)
 218     >
 219 {
 220 private:
 221     typedef typename substitute< R, Dest, Source >::type r;
 222     BOOST_MPL_PP_REPEAT(i, BOOST_VARIANT_AUX_SUBSTITUTE_TYPEDEF, _)
 223
 224 public:
 225     typedef r (*type)( BOOST_MPL_PP_PARAMS(i,u) );
 226 };
 227
 228 #elif i == 0
 229
 230 //
 231 // zero-arg function specialization
 232 //
 233 template <
 234       typename R, typename Dest, typename Source
 235     >
 236 struct substitute<
 237       R (*)( void )
 238     , Dest
 239     , Source
 240       BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(mpl::int_<-1>)
 241     >
 242 {
 243 private:
 244     typedef typename substitute< R, Dest, Source >::type r;
 245
 246 public:
 247     typedef r (*type)( void );
 248 };
 249
 250 #endif // i
 251
 252 #undef i
 253 #endif // BOOST_PP_IS_ITERATING