ceph/src/boost/libs/flyweight/include/boost/flyweight/detail/default_value_policy.hpp

   1 /* Copyright 2006-2014 Joaquin M Lopez Munoz.
   2  * Distributed under the Boost Software License, Version 1.0.
   3  * (See accompanying file LICENSE_1_0.txt or copy at
   4  * http://www.boost.org/LICENSE_1_0.txt)
   5  *
   6  * See http://www.boost.org/libs/flyweight for library home page.
   7  */
   8
   9 #ifndef BOOST_FLYWEIGHT_DETAIL_DEFAULT_VALUE_POLICY_HPP
  10 #define BOOST_FLYWEIGHT_DETAIL_DEFAULT_VALUE_POLICY_HPP
  11
  12 #if defined(_MSC_VER)
  13 #pragma once
  14 #endif
  15
  16 #include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */
  17 #include <boost/detail/workaround.hpp>
  18 #include <boost/flyweight/detail/perfect_fwd.hpp>
  19 #include <boost/flyweight/detail/value_tag.hpp>
  20
  21 /* Default value policy: the key is the same as the value.
  22  */
  23
  24 namespace boost{
  25
  26 namespace flyweights{
  27
  28 namespace detail{
  29
  30 template<typename Value>
  31 struct default_value_policy:value_marker
  32 {
  33   typedef Value key_type;
  34   typedef Value value_type;
  35
  36   struct rep_type
  37   {
  38   /* template ctors */
  39
  40 #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)&&\
  41     !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)&&\
  42     BOOST_WORKAROUND(__GNUC__,<=4)&&(__GNUC__<4||__GNUC_MINOR__<=4)
  43
  44 /* GCC 4.4.2 (and probably prior) bug: the default ctor generated by the
  45  * variadic temmplate ctor below fails to value-initialize x.
  46  */
  47
  48     rep_type():x(){}
  49 #endif
  50
  51 #define BOOST_FLYWEIGHT_PERFECT_FWD_CTR_BODY(args) \
  52   :x(BOOST_FLYWEIGHT_FORWARD(args)){}
  53
  54   BOOST_FLYWEIGHT_PERFECT_FWD(
  55     explicit rep_type,
  56     BOOST_FLYWEIGHT_PERFECT_FWD_CTR_BODY)
  57
  58 #undef BOOST_FLYWEIGHT_PERFECT_FWD_CTR_BODY
  59
  60     rep_type(const rep_type& r):x(r.x){}
  61
  62 #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
  63     rep_type(rep_type&& r):x(std::move(r.x)){}
  64 #endif
  65
  66     operator const value_type&()const{return x;}
  67
  68     value_type x;
  69   };
  70
  71   static void construct_value(const rep_type&){}
  72   static void copy_value(const rep_type&){}
  73
  74 #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
  75   static void move_value(const rep_type&){}
  76 #endif
  77 };
  78
  79 } /* namespace flyweights::detail */
  80
  81 } /* namespace flyweights */
  82
  83 } /* namespace boost */
  84
  85 #endif