1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
|
///////////////////////////////////////////////////////////////////////////////
/// \file utility.hpp
/// Proto callables for things found in the std \<utility\> header
//
// Copyright 2010 Eric Niebler. Distributed under the Boost
// Software License, Version 1.0. (See accompanying file
// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
#ifndef BOOST_PROTO_FUNCTIONAL_STD_UTILITY_HPP_EAN_11_27_2010
#define BOOST_PROTO_FUNCTIONAL_STD_UTILITY_HPP_EAN_11_27_2010
#include <utility>
#include <boost/type_traits/remove_const.hpp>
#include <boost/type_traits/remove_reference.hpp>
#include <boost/proto/proto_fwd.hpp>
namespace boost { namespace proto { namespace functional
{
/// \brief A PolymorphicFunctionObject type that invokes the
/// \c std::make_pair() algorithm on its arguments.
///
/// A PolymorphicFunctionObject type that invokes the
/// \c std::make_pair() algorithm on its arguments.
struct make_pair
{
BOOST_PROTO_CALLABLE()
template<typename Sig>
struct result;
template<typename This, typename First, typename Second>
struct result<This(First, Second)>
{
typedef
std::pair<
typename remove_const<typename remove_reference<First>::type>::type
, typename remove_const<typename remove_reference<Second>::type>::type
>
type;
};
template<typename First, typename Second>
std::pair<First, Second> operator()(First const &first, Second const &second) const
{
return std::make_pair(first, second);
}
};
/// \brief A PolymorphicFunctionObject type that returns
/// the first element of a std::pair.
///
/// A PolymorphicFunctionObject type that returns
/// the first element of a std::pair..
struct first
{
BOOST_PROTO_CALLABLE()
template<typename Sig>
struct result;
template<typename This, typename Pair>
struct result<This(Pair)>
{
typedef typename Pair::first_type type;
};
template<typename This, typename Pair>
struct result<This(Pair &)>
{
typedef typename Pair::first_type &type;
};
template<typename This, typename Pair>
struct result<This(Pair const &)>
{
typedef typename Pair::first_type const &type;
};
template<typename Pair>
typename Pair::first_type &operator()(Pair &pair) const
{
return pair.first;
}
template<typename Pair>
typename Pair::first_type const &operator()(Pair const &pair) const
{
return pair.first;
}
};
/// \brief A PolymorphicFunctionObject type that returns
/// the second element of a std::pair.
///
/// A PolymorphicFunctionObject type that returns
/// the second element of a std::pair..
struct second
{
BOOST_PROTO_CALLABLE()
template<typename Sig>
struct result;
template<typename This, typename Pair>
struct result<This(Pair)>
{
typedef typename Pair::second_type type;
};
template<typename This, typename Pair>
struct result<This(Pair &)>
{
typedef typename Pair::second_type &type;
};
template<typename This, typename Pair>
struct result<This(Pair const &)>
{
typedef typename Pair::second_type const &type;
};
template<typename Pair>
typename Pair::second_type &operator()(Pair &pair) const
{
return pair.second;
}
template<typename Pair>
typename Pair::second_type const &operator()(Pair const &pair) const
{
return pair.second;
}
};
}}}
#endif
|