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
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
|
// tuple_comparison.hpp -----------------------------------------------------
//
// Copyright (C) 2001 Jaakko Jarvi (jaakko.jarvi@cs.utu.fi)
// Copyright (C) 2001 Gary Powell (gary.powell@sierra.com)
//
// 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)
//
// For more information, see http://www.boost.org
//
// (The idea and first impl. of comparison operators was from Doug Gregor)
// -----------------------------------------------------------------
#ifndef BOOST_TUPLE_COMPARISON_HPP
#define BOOST_TUPLE_COMPARISON_HPP
#include "boost/tuple/tuple.hpp"
// -------------------------------------------------------------
// equality and comparison operators
//
// == and != compare tuples elementwise
// <, >, <= and >= use lexicographical ordering
//
// Any operator between tuples of different length fails at compile time
// No dependencies between operators are assumed
// (i.e. !(a<b) does not imply a>=b, a!=b does not imply a==b etc.
// so any weirdnesses of elementary operators are respected).
//
// -------------------------------------------------------------
namespace boost {
namespace tuples {
inline bool operator==(const null_type&, const null_type&) { return true; }
inline bool operator>=(const null_type&, const null_type&) { return true; }
inline bool operator<=(const null_type&, const null_type&) { return true; }
inline bool operator!=(const null_type&, const null_type&) { return false; }
inline bool operator<(const null_type&, const null_type&) { return false; }
inline bool operator>(const null_type&, const null_type&) { return false; }
namespace detail {
// comparison operators check statically the length of its operands and
// delegate the comparing task to the following functions. Hence
// the static check is only made once (should help the compiler).
// These functions assume tuples to be of the same length.
template<class T1, class T2>
inline bool eq(const T1& lhs, const T2& rhs) {
return lhs.get_head() == rhs.get_head() &&
eq(lhs.get_tail(), rhs.get_tail());
}
template<>
inline bool eq<null_type,null_type>(const null_type&, const null_type&) { return true; }
template<class T1, class T2>
inline bool neq(const T1& lhs, const T2& rhs) {
return lhs.get_head() != rhs.get_head() ||
neq(lhs.get_tail(), rhs.get_tail());
}
template<>
inline bool neq<null_type,null_type>(const null_type&, const null_type&) { return false; }
template<class T1, class T2>
inline bool lt(const T1& lhs, const T2& rhs) {
return lhs.get_head() < rhs.get_head() ||
( !(rhs.get_head() < lhs.get_head()) &&
lt(lhs.get_tail(), rhs.get_tail()));
}
template<>
inline bool lt<null_type,null_type>(const null_type&, const null_type&) { return false; }
template<class T1, class T2>
inline bool gt(const T1& lhs, const T2& rhs) {
return lhs.get_head() > rhs.get_head() ||
( !(rhs.get_head() > lhs.get_head()) &&
gt(lhs.get_tail(), rhs.get_tail()));
}
template<>
inline bool gt<null_type,null_type>(const null_type&, const null_type&) { return false; }
template<class T1, class T2>
inline bool lte(const T1& lhs, const T2& rhs) {
return lhs.get_head() <= rhs.get_head() &&
( !(rhs.get_head() <= lhs.get_head()) ||
lte(lhs.get_tail(), rhs.get_tail()));
}
template<>
inline bool lte<null_type,null_type>(const null_type&, const null_type&) { return true; }
template<class T1, class T2>
inline bool gte(const T1& lhs, const T2& rhs) {
return lhs.get_head() >= rhs.get_head() &&
( !(rhs.get_head() >= lhs.get_head()) ||
gte(lhs.get_tail(), rhs.get_tail()));
}
template<>
inline bool gte<null_type,null_type>(const null_type&, const null_type&) { return true; }
} // end of namespace detail
// equal ----
template<class T1, class T2, class S1, class S2>
inline bool operator==(const cons<T1, T2>& lhs, const cons<S1, S2>& rhs)
{
// check that tuple lengths are equal
BOOST_STATIC_ASSERT(length<T2>::value == length<S2>::value);
return detail::eq(lhs, rhs);
}
// not equal -----
template<class T1, class T2, class S1, class S2>
inline bool operator!=(const cons<T1, T2>& lhs, const cons<S1, S2>& rhs)
{
// check that tuple lengths are equal
BOOST_STATIC_ASSERT(length<T2>::value == length<S2>::value);
return detail::neq(lhs, rhs);
}
// <
template<class T1, class T2, class S1, class S2>
inline bool operator<(const cons<T1, T2>& lhs, const cons<S1, S2>& rhs)
{
// check that tuple lengths are equal
BOOST_STATIC_ASSERT(length<T2>::value == length<S2>::value);
return detail::lt(lhs, rhs);
}
// >
template<class T1, class T2, class S1, class S2>
inline bool operator>(const cons<T1, T2>& lhs, const cons<S1, S2>& rhs)
{
// check that tuple lengths are equal
BOOST_STATIC_ASSERT(length<T2>::value == length<S2>::value);
return detail::gt(lhs, rhs);
}
// <=
template<class T1, class T2, class S1, class S2>
inline bool operator<=(const cons<T1, T2>& lhs, const cons<S1, S2>& rhs)
{
// check that tuple lengths are equal
BOOST_STATIC_ASSERT(length<T2>::value == length<S2>::value);
return detail::lte(lhs, rhs);
}
// >=
template<class T1, class T2, class S1, class S2>
inline bool operator>=(const cons<T1, T2>& lhs, const cons<S1, S2>& rhs)
{
// check that tuple lengths are equal
BOOST_STATIC_ASSERT(length<T2>::value == length<S2>::value);
return detail::gte(lhs, rhs);
}
} // end of namespace tuples
} // end of namespace boost
#endif // BOOST_TUPLE_COMPARISON_HPP
|
