boost/concept/detail/concept_def.hpp

   1 // Copyright David Abrahams 2006. Distributed under the Boost
   2 // Software License, Version 1.0. (See accompanying
   3 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   4 #ifndef BOOST_CONCEPT_DETAIL_CONCEPT_DEF_DWA200651_HPP
   5 # define BOOST_CONCEPT_DETAIL_CONCEPT_DEF_DWA200651_HPP
   6 # include <boost/preprocessor/seq/for_each_i.hpp>
   7 # include <boost/preprocessor/seq/enum.hpp>
   8 # include <boost/preprocessor/comma_if.hpp>
   9 # include <boost/preprocessor/cat.hpp>
  10 #endif // BOOST_CONCEPT_DETAIL_CONCEPT_DEF_DWA200651_HPP
  11
  12 // BOOST_concept(SomeName, (p1)(p2)...(pN))
  13 //
  14 // Expands to "template <class p1, class p2, ...class pN> struct SomeName"
  15 //
  16 // Also defines an equivalent SomeNameConcept for backward compatibility.
  17 // Maybe in the next release we can kill off the "Concept" suffix for good.
  18 #if BOOST_WORKAROUND(__GNUC__, <= 3)
  19 # define BOOST_concept(name, params)                                            \
  20     template < BOOST_PP_SEQ_FOR_EACH_I(BOOST_CONCEPT_typename,~,params) >       \
  21     struct name; /* forward declaration */                                      \
  22                                                                                 \
  23     template < BOOST_PP_SEQ_FOR_EACH_I(BOOST_CONCEPT_typename,~,params) >       \
  24     struct BOOST_PP_CAT(name,Concept)                                           \
  25       : name< BOOST_PP_SEQ_ENUM(params) >                                       \
  26     {                                                                           \
  27         /* at least 2.96 and 3.4.3 both need this */                            \
  28         BOOST_PP_CAT(name,Concept)();                                           \
  29     };                                                                          \
  30                                                                                 \
  31     template < BOOST_PP_SEQ_FOR_EACH_I(BOOST_CONCEPT_typename,~,params) >       \
  32     struct name
  33 #else
  34 # define BOOST_concept(name, params)                                            \
  35     template < BOOST_PP_SEQ_FOR_EACH_I(BOOST_CONCEPT_typename,~,params) >       \
  36     struct name; /* forward declaration */                                      \
  37                                                                                 \
  38     template < BOOST_PP_SEQ_FOR_EACH_I(BOOST_CONCEPT_typename,~,params) >       \
  39     struct BOOST_PP_CAT(name,Concept)                                           \
  40       : name< BOOST_PP_SEQ_ENUM(params) >                                       \
  41     {                                                                           \
  42     };                                                                          \
  43                                                                                 \
  44     template < BOOST_PP_SEQ_FOR_EACH_I(BOOST_CONCEPT_typename,~,params) >       \
  45     struct name
  46 #endif
  47
  48 // Helper for BOOST_concept, above.
  49 # define BOOST_CONCEPT_typename(r, ignored, index, t) \
  50     BOOST_PP_COMMA_IF(index) typename t
  51