ceph/src/boost/boost/concept_check/has_constraints.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_CHECK_HAS_CONSTRAINTS_DWA2006429_HPP
   5 # define BOOST_CONCEPT_CHECK_HAS_CONSTRAINTS_DWA2006429_HPP
   6
   7 namespace boost { namespace concept_checking {
   8
   9 // Here we implement the "metafunction" that detects whether a
  10 // constraints metafunction exists
  11 typedef char yes;
  12 typedef char (&no)[2];
  13
  14 template <class Model, void (Model::*)()>
  15 struct wrap_constraints {};
  16
  17 template <class Model>
  18 inline yes has_constraints_(Model*, wrap_constraints<Model,&Model::constraints>* = 0);
  19 inline no has_constraints_(...);
  20
  21 template <class Model>
  22 struct has_constraints
  23 {
  24     BOOST_STATIC_CONSTANT(
  25         bool
  26       , value = sizeof( concept_checking::has_constraints_((Model*)0) ) == 1 );
  27 };
  28
  29 }} // namespace boost::concept_checking
  30
  31 #endif // BOOST_CONCEPT_CHECK_HAS_CONSTRAINTS_DWA2006429_HPP