1// Boost.Bimap
2//
3// Copyright (c) 2006-2007 Matias Capeletto
4//
5// Distributed under the Boost Software License, Version 1.0.
6// (See accompanying file LICENSE_1_0.txt or copy at
7// http://www.boost.org/LICENSE_1_0.txt)
8
9/// \file relation/support/value_type_of.hpp
10/// \brief value_type_of<tag,relation> metafunction
11
12#ifndef BOOST_BIMAP_RELATION_SUPPORT_VALUE_TYPE_OF_HPP
13#define BOOST_BIMAP_RELATION_SUPPORT_VALUE_TYPE_OF_HPP
14
15#if defined(_MSC_VER)
16#pragma once
17#endif
18
19#include <boost/config.hpp>
20
21#include <boost/bimap/relation/detail/metadata_access_builder.hpp>
22
23/** \struct boost::bimaps::relation::support::value_type_of
24
25\brief Metafunction to obtain the value type of one of the sides.
26
27\code
28
29template< class Tag, class Relation >
30struct value_type_of
31{
32 typedef typename Relation::{side}_type type;
33};
34
35\endcode
36
37See also member_at, get().
38\ingroup relation_group
39 **/
40
41namespace boost {
42namespace bimaps {
43namespace relation {
44namespace support {
45
46// Metafunction value_type_of
47/*
48
49 template< class Tag, class Relation >
50 struct value_type_of
51 {
52 typedef -unspecified- type;
53 };
54
55*/
56
57BOOST_BIMAP_SYMMETRIC_METADATA_ACCESS_BUILDER
58(
59 value_type_of,
60 left_value_type,
61 right_value_type
62)
63
64// Add support for info tags to value_type_of
65
66template< class Tag, class SymmetricType >
67struct value_type_of
68<
69 Tag, SymmetricType,
70 BOOST_DEDUCED_TYPENAME enable_if
71 <
72 ::boost::bimaps::relation::support::is_tag_of_member_at_info
73 <
74 Tag,
75 SymmetricType
76 >
77
78 >::type
79>
80{
81 typedef BOOST_DEDUCED_TYPENAME SymmetricType::info_type type;
82};
83
84} // namespace support
85} // namespace relation
86} // namespace bimaps
87} // namespace boost
88
89
90#endif // BOOST_BIMAP_RELATION_SUPPORT_VALUE_TYPE_OF_HPP
91
92

source code of boost/libs/bimap/include/boost/bimap/relation/support/value_type_of.hpp