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
|
// Boost enable_if library
// Copyright 2003 (c) The Trustees of Indiana University.
// Use, modification, and distribution is subject to 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)
// Authors: Jaakko Jarvi (jajarvi at osl.iu.edu)
// Jeremiah Willcock (jewillco at osl.iu.edu)
// Andrew Lumsdaine (lums at osl.iu.edu)
#ifndef BOOST_CORE_ENABLE_IF_HPP
#define BOOST_CORE_ENABLE_IF_HPP
#include "boost/config.hpp"
// Even the definition of enable_if causes problems on some compilers,
// so it's macroed out for all compilers that do not support SFINAE
#ifndef BOOST_NO_SFINAE
namespace boost
{
template<typename T, typename R=void>
struct enable_if_has_type
{
typedef R type;
};
template <bool B, class T = void>
struct enable_if_c {
typedef T type;
};
template <class T>
struct enable_if_c<false, T> {};
template <class Cond, class T = void>
struct enable_if : public enable_if_c<Cond::value, T> {};
template <bool B, class T>
struct lazy_enable_if_c {
typedef typename T::type type;
};
template <class T>
struct lazy_enable_if_c<false, T> {};
template <class Cond, class T>
struct lazy_enable_if : public lazy_enable_if_c<Cond::value, T> {};
template <bool B, class T = void>
struct disable_if_c {
typedef T type;
};
template <class T>
struct disable_if_c<true, T> {};
template <class Cond, class T = void>
struct disable_if : public disable_if_c<Cond::value, T> {};
template <bool B, class T>
struct lazy_disable_if_c {
typedef typename T::type type;
};
template <class T>
struct lazy_disable_if_c<true, T> {};
template <class Cond, class T>
struct lazy_disable_if : public lazy_disable_if_c<Cond::value, T> {};
} // namespace boost
#else
namespace boost {
namespace detail { typedef void enable_if_default_T; }
template <typename T>
struct enable_if_does_not_work_on_this_compiler;
template<typename T, typename R=void>
struct enable_if_has_type : enable_if_does_not_work_on_this_compiler<T>
{ };
template <bool B, class T = detail::enable_if_default_T>
struct enable_if_c : enable_if_does_not_work_on_this_compiler<T>
{ };
template <bool B, class T = detail::enable_if_default_T>
struct disable_if_c : enable_if_does_not_work_on_this_compiler<T>
{ };
template <bool B, class T = detail::enable_if_default_T>
struct lazy_enable_if_c : enable_if_does_not_work_on_this_compiler<T>
{ };
template <bool B, class T = detail::enable_if_default_T>
struct lazy_disable_if_c : enable_if_does_not_work_on_this_compiler<T>
{ };
template <class Cond, class T = detail::enable_if_default_T>
struct enable_if : enable_if_does_not_work_on_this_compiler<T>
{ };
template <class Cond, class T = detail::enable_if_default_T>
struct disable_if : enable_if_does_not_work_on_this_compiler<T>
{ };
template <class Cond, class T = detail::enable_if_default_T>
struct lazy_enable_if : enable_if_does_not_work_on_this_compiler<T>
{ };
template <class Cond, class T = detail::enable_if_default_T>
struct lazy_disable_if : enable_if_does_not_work_on_this_compiler<T>
{ };
} // namespace boost
#endif // BOOST_NO_SFINAE
#endif
|
