1 | #ifndef BOOST_SERIALIZATION_VARIANT_HPP |
2 | #define BOOST_SERIALIZATION_VARIANT_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 | // variant.hpp - non-intrusive serialization of variant types |
11 | // |
12 | // copyright (c) 2005 |
13 | // troy d. straszheim <troy@resophonic.com> |
14 | // http://www.resophonic.com |
15 | // |
16 | // Use, modification and distribution is subject to the Boost Software |
17 | // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at |
18 | // http://www.boost.org/LICENSE_1_0.txt) |
19 | // |
20 | // See http://www.boost.org for updates, documentation, and revision history. |
21 | // |
22 | // thanks to Robert Ramey, Peter Dimov, and Richard Crossley. |
23 | // |
24 | |
25 | #include <boost/mpl/front.hpp> |
26 | #include <boost/mpl/pop_front.hpp> |
27 | #include <boost/mpl/eval_if.hpp> |
28 | #include <boost/mpl/identity.hpp> |
29 | #include <boost/mpl/size.hpp> |
30 | #include <boost/mpl/empty.hpp> |
31 | |
32 | #include <boost/serialization/throw_exception.hpp> |
33 | |
34 | #include <boost/variant.hpp> |
35 | |
36 | #include <boost/archive/archive_exception.hpp> |
37 | |
38 | #include <boost/serialization/split_free.hpp> |
39 | #include <boost/serialization/serialization.hpp> |
40 | #include <boost/serialization/nvp.hpp> |
41 | |
42 | namespace boost { |
43 | namespace serialization { |
44 | |
45 | template<class Archive> |
46 | struct variant_save_visitor : |
47 | boost::static_visitor<> |
48 | { |
49 | variant_save_visitor(Archive& ar) : |
50 | m_ar(ar) |
51 | {} |
52 | template<class T> |
53 | void operator()(T const & value) const |
54 | { |
55 | m_ar << BOOST_SERIALIZATION_NVP(value); |
56 | } |
57 | private: |
58 | Archive & m_ar; |
59 | }; |
60 | |
61 | template<class Archive, BOOST_VARIANT_ENUM_PARAMS(/* typename */ class T)> |
62 | void save( |
63 | Archive & ar, |
64 | boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> const & v, |
65 | unsigned int /*version*/ |
66 | ){ |
67 | int which = v.which(); |
68 | ar << BOOST_SERIALIZATION_NVP(which); |
69 | variant_save_visitor<Archive> visitor(ar); |
70 | v.apply_visitor(visitor); |
71 | } |
72 | |
73 | template<class S> |
74 | struct variant_impl { |
75 | |
76 | struct load_null { |
77 | template<class Archive, class V> |
78 | static void invoke( |
79 | Archive & /*ar*/, |
80 | int /*which*/, |
81 | V & /*v*/, |
82 | const unsigned int /*version*/ |
83 | ){} |
84 | }; |
85 | |
86 | struct load_impl { |
87 | template<class Archive, class V> |
88 | static void invoke( |
89 | Archive & ar, |
90 | int which, |
91 | V & v, |
92 | const unsigned int version |
93 | ){ |
94 | if(which == 0){ |
95 | // note: A non-intrusive implementation (such as this one) |
96 | // necessary has to copy the value. This wouldn't be necessary |
97 | // with an implementation that de-serialized to the address of the |
98 | // aligned storage included in the variant. |
99 | typedef typename mpl::front<S>::type head_type; |
100 | head_type value; |
101 | ar >> BOOST_SERIALIZATION_NVP(value); |
102 | v = value; |
103 | ar.reset_object_address(& boost::get<head_type>(v), & value); |
104 | return; |
105 | } |
106 | typedef typename mpl::pop_front<S>::type type; |
107 | variant_impl<type>::load(ar, which - 1, v, version); |
108 | } |
109 | }; |
110 | |
111 | template<class Archive, class V> |
112 | static void load( |
113 | Archive & ar, |
114 | int which, |
115 | V & v, |
116 | const unsigned int version |
117 | ){ |
118 | typedef typename mpl::eval_if<mpl::empty<S>, |
119 | mpl::identity<load_null>, |
120 | mpl::identity<load_impl> |
121 | >::type typex; |
122 | typex::invoke(ar, which, v, version); |
123 | } |
124 | |
125 | }; |
126 | |
127 | template<class Archive, BOOST_VARIANT_ENUM_PARAMS(/* typename */ class T)> |
128 | void load( |
129 | Archive & ar, |
130 | boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>& v, |
131 | const unsigned int version |
132 | ){ |
133 | int which; |
134 | typedef typename boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>::types types; |
135 | ar >> BOOST_SERIALIZATION_NVP(which); |
136 | if(which >= mpl::size<types>::value) |
137 | // this might happen if a type was removed from the list of variant types |
138 | boost::serialization::throw_exception( |
139 | e: boost::archive::archive_exception( |
140 | boost::archive::archive_exception::unsupported_version |
141 | ) |
142 | ); |
143 | variant_impl<types>::load(ar, which, v, version); |
144 | } |
145 | |
146 | template<class Archive,BOOST_VARIANT_ENUM_PARAMS(/* typename */ class T)> |
147 | inline void serialize( |
148 | Archive & ar, |
149 | boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> & v, |
150 | const unsigned int file_version |
151 | ){ |
152 | split_free(ar,v,file_version); |
153 | } |
154 | |
155 | } // namespace serialization |
156 | } // namespace boost |
157 | |
158 | #endif //BOOST_SERIALIZATION_VARIANT_HPP |
159 | |