ceph/src/boost/libs/concept_check/include/boost/concept/detail/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_DETAIL_HAS_CONSTRAINTS_DWA2006429_HPP
   5 # define BOOST_CONCEPT_DETAIL_HAS_CONSTRAINTS_DWA2006429_HPP
   6
   7 # include <boost/mpl/bool.hpp>
   8 # include <boost/detail/workaround.hpp>
   9 # include <boost/concept/detail/backward_compatibility.hpp>
  10
  11 namespace boost { namespace concepts {
  12
  13 namespace detail
  14 {
  15
  16 // Here we implement the metafunction that detects whether a
  17 // constraints metafunction exists
  18   typedef char yes;
  19   typedef char (&no)[2];
  20
  21   template <class Model, void (Model::*)()>
  22   struct wrap_constraints {};
  23
  24 #if BOOST_WORKAROUND(__SUNPRO_CC, <= 0x580) || defined(__CUDACC__)
  25   // Work around the following bogus error in Sun Studio 11, by
  26   // turning off the has_constraints function entirely:
  27   //    Error: complex expression not allowed in dependent template
  28   //    argument expression
  29   inline no has_constraints_(...);
  30 #else
  31   template <class Model>
  32   inline yes has_constraints_(Model*, wrap_constraints<Model,&Model::constraints>* = 0);
  33   inline no has_constraints_(...);
  34 #endif
  35 }
  36
  37 // This would be called "detail::has_constraints," but it has a strong
  38 // tendency to show up in error messages.
  39 template <class Model>
  40 struct not_satisfied
  41 {
  42     BOOST_STATIC_CONSTANT(
  43         bool
  44       , value = sizeof( detail::has_constraints_((Model*)0) ) == sizeof(detail::yes) );
  45     typedef mpl::bool_<value> type;
  46 };
  47
  48 }} // namespace boost::concepts::detail
  49
  50 #endif // BOOST_CONCEPT_DETAIL_HAS_CONSTRAINTS_DWA2006429_HPP