ceph/src/boost/libs/icl/include/boost/icl/type_traits/predicate.hpp

   1 /*-----------------------------------------------------------------------------+
   2 Copyright (c) 2010-2010: Joachim Faulhaber
   3 +------------------------------------------------------------------------------+
   4    Distributed under the Boost Software License, Version 1.0.
   5       (See accompanying file LICENCE.txt or copy at
   6            http://www.boost.org/LICENSE_1_0.txt)
   7 +-----------------------------------------------------------------------------*/
   8 #ifndef BOOST_ICL_TYPE_TRAITS_PREDICATE_HPP_JOFA_101102
   9 #define BOOST_ICL_TYPE_TRAITS_PREDICATE_HPP_JOFA_101102
  10
  11 #include <functional>
  12
  13 namespace boost{namespace icl
  14 {
  15     // naming convention
  16     // predicate: n-ary predicate
  17     // property:  unary predicate
  18     // relation:  binary predicate
  19
  20     // Unary predicates
  21
  22     template <class Type>
  23     class property : public std::unary_function<Type,bool>{};
  24
  25     template <class Type>
  26     class member_property : public property<Type>
  27     {
  28     public:
  29         member_property( bool(Type::* pred)()const ): property<Type>(), m_pred(pred){}
  30         bool operator()(const Type& x)const { return (x.*m_pred)(); }
  31     private:
  32         bool(Type::* m_pred)()const;
  33     } ;
  34
  35     // Binary predicates: relations
  36
  37     template <class LeftT, class RightT>
  38     class relation : public std::binary_function<LeftT,RightT,bool>{};
  39
  40
  41 }} // namespace icl boost
  42
  43 #endif
  44