boost/flyweight/detail/serialization_helper.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_SERIALIZATION_HELPER_HPP
  10 #define BOOST_FLYWEIGHT_DETAIL_SERIALIZATION_HELPER_HPP
  11
  12 #if defined(_MSC_VER)&&(_MSC_VER>=1200)
  13 #pragma once
  14 #endif
  15
  16 #include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */
  17 #include <boost/multi_index_container.hpp>
  18 #include <boost/multi_index/hashed_index.hpp>
  19 #include <boost/multi_index/random_access_index.hpp>
  20 #include <boost/noncopyable.hpp>
  21 #include <boost/serialization/extended_type_info.hpp>
  22 #include <vector>
  23
  24 namespace boost{
  25
  26 namespace flyweights{
  27
  28 namespace detail{
  29
  30 /* The serialization helpers for flyweight<T> map numerical IDs to
  31  * flyweight exemplars --an exemplar is the flyweight object
  32  * associated to a given value that appears first on the serialization
  33  * stream, so that subsequent equivalent flyweight objects will be made
  34  * to refer to it during the serialization process.
  35  */
  36
  37 template<typename Flyweight>
  38 struct flyweight_value_address
  39 {
  40   typedef const typename Flyweight::value_type* result_type;
  41
  42   result_type operator()(const Flyweight& x)const{return &x.get();}
  43 };
  44
  45 template<typename Flyweight>
  46 class save_helper:private noncopyable
  47 {
  48   typedef multi_index::multi_index_container<
  49     Flyweight,
  50     multi_index::indexed_by<
  51       multi_index::random_access<>,
  52       multi_index::hashed_unique<flyweight_value_address<Flyweight> >
  53     >
  54   > table;
  55
  56 public:
  57
  58   typedef typename table::size_type size_type;
  59
  60   size_type size()const{return t.size();}
  61
  62   size_type find(const Flyweight& x)const
  63   {
  64     return multi_index::project<0>(t,multi_index::get<1>(t).find(&x.get()))
  65              -t.begin();
  66   }
  67
  68   void push_back(const Flyweight& x){t.push_back(x);}
  69
  70 private:
  71   table t;
  72 };
  73
  74 template<typename Flyweight>
  75 class load_helper:private noncopyable
  76 {
  77   typedef std::vector<Flyweight> table;
  78
  79 public:
  80
  81   typedef typename table::size_type size_type;
  82
  83   size_type size()const{return t.size();}
  84
  85   Flyweight operator[](size_type n)const{return t[n];}
  86
  87   void push_back(const Flyweight& x){t.push_back(x);}
  88
  89 private:
  90   table t;
  91 };
  92
  93 } /* namespace flyweights::detail */
  94
  95 } /* namespace flyweights */
  96
  97 } /* namespace boost */
  98
  99 #endif