| // Copyright David Abrahams 2006. Distributed under the Boost |
| // Software License, Version 1.0. (See accompanying |
| // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
| #ifndef BOOST_CONCEPT_CHECK_HAS_CONSTRAINTS_DWA2006429_HPP |
| # define BOOST_CONCEPT_CHECK_HAS_CONSTRAINTS_DWA2006429_HPP |
| |
| namespace boost { namespace concept_checking { |
| |
| // Here we implement the "metafunction" that detects whether a |
| // constraints metafunction exists |
| typedef char yes; |
| typedef char (&no)[2]; |
| |
| template <class Model, void (Model::*)()> |
| struct wrap_constraints {}; |
| |
| template <class Model> |
| inline yes has_constraints_(Model*, wrap_constraints<Model,&Model::constraints>* = 0); |
| inline no has_constraints_(...); |
| |
| template <class Model> |
| struct has_constraints |
| { |
| BOOST_STATIC_CONSTANT( |
| bool |
| , value = sizeof( concept_checking::has_constraints_((Model*)0) ) == 1 ); |
| }; |
| |
| }} // namespace boost::concept_checking |
| |
| #endif // BOOST_CONCEPT_CHECK_HAS_CONSTRAINTS_DWA2006429_HPP |