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

   1 /*-----------------------------------------------------------------------------+
   2 Copyright (c) 2008-2009: 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_IDENTITY_ELEMENT_HPP_JOFA_080912
   9 #define BOOST_ICL_TYPE_TRAITS_IDENTITY_ELEMENT_HPP_JOFA_080912
  10
  11 #include <boost/icl/type_traits/type_to_string.hpp>
  12
  13 namespace boost{ namespace icl
  14 {
  15     template <class Type> struct identity_element
  16     {
  17         static Type value();
  18         Type operator()()const { return value(); }
  19     };
  20
  21     template <class Type>
  22     inline Type identity_element<Type>::value()
  23     {
  24         static Type _value;
  25         return _value;
  26     }
  27
  28     template<>
  29     inline std::string unary_template_to_string<identity_element>::apply() { return "0"; }
  30
  31 }} // namespace boost icl
  32
  33 #endif
  34
  35