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
|
/*
Copyright 2018 Glen Joseph Fernandes
(glenjofe@gmail.com)
Distributed under the Boost Software License, Version 1.0.
(http://www.boost.org/LICENSE_1_0.txt)
*/
#include <boost/core/exchange.hpp>
#include <boost/core/lightweight_test.hpp>
void test1()
{
int i = 1;
BOOST_TEST(boost::exchange(i, 2) == 1);
BOOST_TEST(i == 2);
}
class C1 {
public:
explicit C1(int i)
: i_(i) { }
int i() const {
return i_;
}
private:
int i_;
};
void test2()
{
C1 x(1);
BOOST_TEST(boost::exchange(x, C1(2)).i() == 1);
BOOST_TEST(x.i() == 2);
}
class C2 {
public:
explicit C2(int i)
: i_(i) { }
operator C1() const {
return C1(i_);
}
int i() const {
return i_;
}
private:
int i_;
};
void test3()
{
C1 x(1);
BOOST_TEST(boost::exchange(x, C2(2)).i() == 1);
BOOST_TEST(x.i() == 2);
}
class C3 {
public:
explicit C3(int i)
: i_(i) { }
C3(const C3& c)
: i_(c.i_) { }
C3& operator=(const C1& c) {
i_ = c.i();
return *this;
}
int i() const {
return i_;
}
private:
C3& operator=(const C3&);
int i_;
};
void test4()
{
C3 x(1);
BOOST_TEST(boost::exchange(x, C1(2)).i() == 1);
BOOST_TEST(x.i() == 2);
}
int main()
{
test1();
test2();
test3();
test4();
return boost::report_errors();
}
|
