1#ifndef BOOST_SERIALIZATION_NVP_HPP
2#define BOOST_SERIALIZATION_NVP_HPP
3
4// MS compatible compilers support #pragma once
5#if defined(_MSC_VER)
6# pragma once
7#endif
8
9/////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8
10// nvp.hpp: interface for serialization system.
11
12// (C) Copyright 2002 Robert Ramey - http://www.rrsd.com .
13// Use, modification and distribution is subject to the Boost Software
14// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
15// http://www.boost.org/LICENSE_1_0.txt)
16
17// See http://www.boost.org for updates, documentation, and revision history.
18
19#include <utility>
20
21#include <boost/config.hpp>
22#include <boost/detail/workaround.hpp>
23
24#include <boost/mpl/integral_c.hpp>
25#include <boost/mpl/integral_c_tag.hpp>
26
27#include <boost/serialization/level.hpp>
28#include <boost/serialization/tracking.hpp>
29#include <boost/serialization/split_member.hpp>
30#include <boost/serialization/base_object.hpp>
31#include <boost/serialization/traits.hpp>
32#include <boost/serialization/wrapper.hpp>
33
34namespace boost {
35namespace serialization {
36
37template<class T>
38struct nvp :
39 public std::pair<const char *, T *>,
40 public wrapper_traits<const nvp< T > >
41{
42 explicit nvp(const char * name_, T & t) :
43 // note: redundant cast works around borland issue
44 // note: added _ to suppress useless gcc warning
45 std::pair<const char *, T *>(name_, (T*)(& t))
46 {}
47 nvp(const nvp & rhs) :
48 // note: redundant cast works around borland issue
49 std::pair<const char *, T *>(rhs.first, (T*)rhs.second)
50 {}
51
52 const char * name() const {
53 return this->first;
54 }
55 T & value() const {
56 return *(this->second);
57 }
58
59 const T & const_value() const {
60 return *(this->second);
61 }
62
63 // True64 compiler complains with a warning about the use of
64 // the name "Archive" hiding some higher level usage. I'm sure this
65 // is an error but I want to accomodated as it generates a long warning
66 // listing and might be related to a lot of test failures.
67 // default treatment for name-value pairs. The name is
68 // just discarded and only the value is serialized.
69 template<class Archivex>
70 void save(
71 Archivex & ar,
72 const unsigned int /* file_version */
73 ) const {
74 // CodeWarrior 8.x can't seem to resolve the << op for a rhs of "const T *"
75 ar.operator<<(const_value());
76 }
77 template<class Archivex>
78 void load(
79 Archivex & ar,
80 const unsigned int /* file_version */
81 ){
82 // CodeWarrior 8.x can't seem to resolve the >> op for a rhs of "const T *"
83 ar.operator>>(value());
84 }
85 BOOST_SERIALIZATION_SPLIT_MEMBER()
86};
87
88template<class T>
89inline
90const nvp< T > make_nvp(const char * name, T & t){
91 return nvp< T >(name, t);
92}
93
94// to maintain efficiency and portability, we want to assign
95// specific serialization traits to all instances of this wrappers.
96// we can't strait forward method below as it depends upon
97// Partial Template Specialization and doing so would mean that wrappers
98// wouldn't be treated the same on different platforms. This would
99// break archive portability. Leave this here as reminder not to use it !!!
100
101template <class T>
102struct implementation_level<nvp< T > >
103{
104 typedef mpl::integral_c_tag tag;
105 typedef mpl::int_<object_serializable> type;
106 BOOST_STATIC_CONSTANT(int, value = implementation_level::type::value);
107};
108
109// nvp objects are generally created on the stack and are never tracked
110template<class T>
111struct tracking_level<nvp< T > >
112{
113 typedef mpl::integral_c_tag tag;
114 typedef mpl::int_<track_never> type;
115 BOOST_STATIC_CONSTANT(int, value = tracking_level::type::value);
116};
117
118
119} // seralization
120} // boost
121
122#include <boost/preprocessor/stringize.hpp>
123
124#define BOOST_SERIALIZATION_NVP(name) \
125 boost::serialization::make_nvp(BOOST_PP_STRINGIZE(name), name)
126/**/
127
128#define BOOST_SERIALIZATION_BASE_OBJECT_NVP(name) \
129 boost::serialization::make_nvp( \
130 BOOST_PP_STRINGIZE(name), \
131 boost::serialization::base_object<name >(*this) \
132 )
133/**/
134
135#endif // BOOST_SERIALIZATION_NVP_HPP
136

source code of boost/boost/serialization/nvp.hpp