Chris@16: // Copyright David Abrahams 2006. Distributed under the Boost
Chris@16: // Software License, Version 1.0. (See accompanying
Chris@16: // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: #ifndef BOOST_CONCEPT_CHECK_HAS_CONSTRAINTS_DWA2006429_HPP
Chris@16: # define BOOST_CONCEPT_CHECK_HAS_CONSTRAINTS_DWA2006429_HPP
Chris@16: 
Chris@16: namespace boost { namespace concept_checking { 
Chris@16: 
Chris@16: // Here we implement the "metafunction" that detects whether a
Chris@16: // constraints metafunction exists
Chris@16: typedef char yes;
Chris@16: typedef char (&no)[2];
Chris@16: 
Chris@16: template <class Model, void (Model::*)()>
Chris@16: struct wrap_constraints {};
Chris@16:     
Chris@16: template <class Model>
Chris@16: inline yes has_constraints_(Model*, wrap_constraints<Model,&Model::constraints>* = 0);
Chris@16: inline no has_constraints_(...);
Chris@16: 
Chris@16: template <class Model>
Chris@16: struct has_constraints
Chris@16: {
Chris@16:     BOOST_STATIC_CONSTANT(
Chris@16:         bool
Chris@16:       , value = sizeof( concept_checking::has_constraints_((Model*)0) ) == 1 );
Chris@16: };
Chris@16: 
Chris@16: }} // namespace boost::concept_checking
Chris@16: 
Chris@16: #endif // BOOST_CONCEPT_CHECK_HAS_CONSTRAINTS_DWA2006429_HPP