concept_def.hpp 1.9 KB

12345678910111213141516171819202122232425262728293031323334
  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. // BOOST_concept(SomeName, (p1)(p2)...(pN))
  12. //
  13. // Expands to "template <class p1, class p2, ...class pN> struct SomeName"
  14. //
  15. // Also defines an equivalent SomeNameConcept for backward compatibility.
  16. // Maybe in the next release we can kill off the "Concept" suffix for good.
  17. # define BOOST_concept(name, params) \
  18. template < BOOST_PP_SEQ_FOR_EACH_I(BOOST_CONCEPT_typename,~,params) > \
  19. struct name; /* forward declaration */ \
  20. \
  21. template < BOOST_PP_SEQ_FOR_EACH_I(BOOST_CONCEPT_typename,~,params) > \
  22. struct BOOST_PP_CAT(name,Concept) \
  23. : name< BOOST_PP_SEQ_ENUM(params) > \
  24. { \
  25. }; \
  26. \
  27. template < BOOST_PP_SEQ_FOR_EACH_I(BOOST_CONCEPT_typename,~,params) > \
  28. struct name
  29. // Helper for BOOST_concept, above.
  30. # define BOOST_CONCEPT_typename(r, ignored, index, t) \
  31. BOOST_PP_COMMA_IF(index) typename t