ceph/src/boost/libs/flyweight/include/boost/flyweight/hashed_factory.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_HASHED_FACTORY_HPP
  10 #define BOOST_FLYWEIGHT_HASHED_FACTORY_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/flyweight/factory_tag.hpp>
  18 #include <boost/flyweight/hashed_factory_fwd.hpp>
  19 #include <boost/multi_index_container.hpp>
  20 #include <boost/multi_index/identity.hpp>
  21 #include <boost/multi_index/hashed_index.hpp>
  22 #include <boost/mpl/aux_/lambda_support.hpp>
  23 #include <boost/mpl/if.hpp>
  24
  25 #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
  26 #include <utility>
  27 #endif
  28
  29 /* Flyweight factory based on a hashed container implemented
  30  * with Boost.MultiIndex.
  31  */
  32
  33 namespace boost{
  34
  35 namespace flyweights{
  36
  37 template<
  38   typename Entry,typename Key,
  39   typename Hash,typename Pred,typename Allocator
  40 >
  41 class hashed_factory_class:public factory_marker
  42 {
  43   struct index_list:
  44     boost::mpl::vector1<
  45       multi_index::hashed_unique<
  46         multi_index::identity<Entry>,
  47         typename boost::mpl::if_<
  48           mpl::is_na<Hash>,
  49           hash<Key>,
  50           Hash
  51         >::type,
  52         typename boost::mpl::if_<
  53           mpl::is_na<Pred>,
  54           std::equal_to<Key>,
  55           Pred
  56         >::type
  57       >
  58     >
  59   {};
  60
  61   typedef multi_index::multi_index_container<
  62     Entry,
  63     index_list,
  64     typename boost::mpl::if_<
  65       mpl::is_na<Allocator>,
  66       std::allocator<Entry>,
  67       Allocator
  68     >::type
  69   > container_type;
  70
  71 public:
  72   typedef const Entry* handle_type;
  73
  74   handle_type insert(const Entry& x)
  75   {
  76     return &*cont.insert(x).first;
  77   }
  78
  79 #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
  80   handle_type insert(Entry&& x)
  81   {
  82     return &*cont.insert(std::move(x)).first;
  83   }
  84 #endif
  85
  86   void erase(handle_type h)
  87   {
  88     cont.erase(cont.iterator_to(*h));
  89   }
  90
  91   static const Entry& entry(handle_type h){return *h;}
  92
  93 private:
  94   container_type cont;
  95
  96 public:
  97   typedef hashed_factory_class type;
  98   BOOST_MPL_AUX_LAMBDA_SUPPORT(
  99     5,hashed_factory_class,(Entry,Key,Hash,Pred,Allocator))
 100 };
 101
 102 /* hashed_factory_class specifier */
 103
 104 template<
 105   typename Hash,typename Pred,typename Allocator
 106   BOOST_FLYWEIGHT_NOT_A_PLACEHOLDER_EXPRESSION_DEF
 107 >
 108 struct hashed_factory:factory_marker
 109 {
 110   template<typename Entry,typename Key>
 111   struct apply:
 112     mpl::apply2<
 113       hashed_factory_class<
 114         boost::mpl::_1,boost::mpl::_2,Hash,Pred,Allocator
 115       >,
 116       Entry,Key
 117     >
 118   {};
 119 };
 120
 121 } /* namespace flyweights */
 122
 123 } /* namespace boost */
 124
 125 #endif