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
|
// Copyright (C) 2003, Fernando Luis Cacciola Carballal.
//
// 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)
//
// See http://www.boost.org/libs/optional for documentation.
//
// You are welcome to contact the author at:
// fernando_cacciola@hotmail.com
//
#ifndef BOOST_UTILITY_COMPARE_POINTEES_25AGO2003_HPP
#define BOOST_UTILITY_COMPARE_POINTEES_25AGO2003_HPP
#include<functional>
namespace boost {
// template<class OP> bool equal_pointees(OP const& x, OP const& y);
// template<class OP> struct equal_pointees_t;
//
// Being OP a model of OptionalPointee (either a pointer or an optional):
//
// If both x and y have valid pointees, returns the result of (*x == *y)
// If only one has a valid pointee, returns false.
// If none have valid pointees, returns true.
// No-throw
template<class OptionalPointee>
inline
bool equal_pointees ( OptionalPointee const& x, OptionalPointee const& y )
{
return (!x) != (!y) ? false : ( !x ? true : (*x) == (*y) ) ;
}
template<class OptionalPointee>
struct equal_pointees_t
{
typedef bool result_type;
typedef OptionalPointee first_argument_type;
typedef OptionalPointee second_argument_type;
bool operator() ( OptionalPointee const& x, OptionalPointee const& y ) const
{ return equal_pointees(x,y) ; }
} ;
// template<class OP> bool less_pointees(OP const& x, OP const& y);
// template<class OP> struct less_pointees_t;
//
// Being OP a model of OptionalPointee (either a pointer or an optional):
//
// If y has not a valid pointee, returns false.
// ElseIf x has not a valid pointee, returns true.
// ElseIf both x and y have valid pointees, returns the result of (*x < *y)
// No-throw
template<class OptionalPointee>
inline
bool less_pointees ( OptionalPointee const& x, OptionalPointee const& y )
{
return !y ? false : ( !x ? true : (*x) < (*y) ) ;
}
template<class OptionalPointee>
struct less_pointees_t
{
typedef bool result_type;
typedef OptionalPointee first_argument_type;
typedef OptionalPointee second_argument_type;
bool operator() ( OptionalPointee const& x, OptionalPointee const& y ) const
{ return less_pointees(x,y) ; }
} ;
} // namespace boost
#endif
|
