ceph/src/boost/libs/type_erasure/include/boost/type_erasure/concept_interface.hpp

   1 // Boost.TypeErasure library
   2 //
   3 // Copyright 2011 Steven Watanabe
   4 //
   5 // Distributed under the Boost Software License Version 1.0. (See
   6 // accompanying file LICENSE_1_0.txt or copy at
   7 // http://www.boost.org/LICENSE_1_0.txt)
   8 //
   9 // $Id$
  10
  11 #ifndef BOOST_TYPE_ERASURE_CONCEPT_INTERFACE_HPP_INCLUDED
  12 #define BOOST_TYPE_ERASURE_CONCEPT_INTERFACE_HPP_INCLUDED
  13
  14 namespace boost {
  15 namespace type_erasure {
  16
  17 /**
  18  * The @ref concept_interface class can be specialized to
  19  * add behavior to an @ref any.  An @ref any inherits from
  20  * all the relevant specializations of @ref concept_interface.
  21  *
  22  * @ref concept_interface can be specialized for either
  23  * primitive or composite concepts.  If a concept @c C1
  24  * contains another concept @c C2, then the library guarantees
  25  * that the specialization of @ref concept_interface for
  26  * @c C2 is a base class of the specialization for @c C1.
  27  * This means that @c C1 can safely override members of @c C2.
  28  *
  29  * @ref concept_interface may only be specialized for user-defined
  30  * concepts.  The library owns the specializations of its own
  31  * built in concepts.
  32  *
  33  * \tparam Concept The concept that we're specializing
  34  *         @ref concept_interface for.  One of its
  35  *         placeholders should be @c ID.
  36  * \tparam Base The base of this class.  Specializations of @ref
  37  *         concept_interface must inherit publicly from this type.
  38  * \tparam ID The placeholder representing this type.
  39  * \tparam Enable A dummy parameter that can be used for SFINAE.
  40  *
  41  * The metafunctions @ref derived, @ref rebind_any, and @ref as_param
  42  * (which can be applied to @c Base) are useful for determining the
  43  * argument and return types of functions defined in @ref concept_interface.
  44  *
  45  * For dispatching the function use \call.
  46  */
  47 template<class Concept, class Base, class ID, class Enable = void>
  48 struct concept_interface : Base {};
  49
  50 }
  51 }
  52
  53 #endif