1// Copyright 2017, 2021 Peter Dimov.
2// Distributed under the Boost Software License, Version 1.0.
3// https://www.boost.org/LICENSE_1_0.txt
4
5#include <boost/system/result.hpp>
6#include <boost/core/lightweight_test.hpp>
7#include <boost/core/lightweight_test_trait.hpp>
8
9using namespace boost::system;
10
11struct X
12{
13 static int instances;
14
15 int v_;
16
17 explicit X( int v ): v_( v ) { ++instances; }
18
19 X( int v1, int v2 ): v_( v1+v2 ) { ++instances; }
20 X( int v1, int v2, int v3 ): v_( v1+v2+v3 ) { ++instances; }
21
22 X( X const& ) = delete;
23 X& operator=( X const& ) = delete;
24
25 ~X() { --instances; }
26};
27
28int X::instances = 0;
29
30int main()
31{
32 {
33 result<int> r( 0 );
34
35 BOOST_TEST( r.has_value() );
36 BOOST_TEST( !r.has_error() );
37
38 BOOST_TEST_EQ( r.value(), 0 );
39 }
40
41 {
42 result<int> r = 0;
43
44 BOOST_TEST( r.has_value() );
45 BOOST_TEST( !r.has_error() );
46
47 BOOST_TEST_EQ( r.value(), 0 );
48 }
49
50 {
51 result<int, int> r( in_place_value, 1 );
52
53 BOOST_TEST( r.has_value() );
54 BOOST_TEST( !r.has_error() );
55
56 BOOST_TEST_EQ( *r, 1 );
57 }
58
59 BOOST_TEST_EQ( X::instances, 0 );
60
61 {
62 result<X> r( 1 );
63
64 BOOST_TEST( r.has_value() );
65 BOOST_TEST( !r.has_error() );
66
67 BOOST_TEST_EQ( r.value().v_, 1 );
68
69 BOOST_TEST_EQ( X::instances, 1 );
70 }
71
72 BOOST_TEST_EQ( X::instances, 0 );
73
74 {
75 result<X> r( 1, 2 );
76
77 BOOST_TEST( r.has_value() );
78 BOOST_TEST( !r.has_error() );
79
80 BOOST_TEST_EQ( r.value().v_, 1+2 );
81
82 BOOST_TEST_EQ( X::instances, 1 );
83 }
84
85 BOOST_TEST_EQ( X::instances, 0 );
86
87 {
88 result<X> r( 1, 2, 3 );
89
90 BOOST_TEST( r.has_value() );
91 BOOST_TEST( !r.has_error() );
92
93 BOOST_TEST_EQ( r.value().v_, 1+2+3 );
94
95 BOOST_TEST_EQ( X::instances, 1 );
96 }
97
98 BOOST_TEST_EQ( X::instances, 0 );
99
100 {
101 result<X, X> r( in_place_value, 1 );
102
103 BOOST_TEST( r.has_value() );
104 BOOST_TEST( !r.has_error() );
105
106 BOOST_TEST_EQ( r->v_, 1 );
107
108 BOOST_TEST_EQ( X::instances, 1 );
109 }
110
111 BOOST_TEST_EQ( X::instances, 0 );
112
113 {
114 BOOST_TEST_TRAIT_TRUE((std::is_constructible<result<int>, int>));
115 BOOST_TEST_TRAIT_TRUE((std::is_convertible<int, result<int>>));
116
117 BOOST_TEST_TRAIT_FALSE((std::is_constructible<result<int, int>, int>));
118 BOOST_TEST_TRAIT_FALSE((std::is_constructible<result<int, float>, int>));
119
120 BOOST_TEST_TRAIT_TRUE((std::is_constructible<result<X>, int>));
121 BOOST_TEST_TRAIT_FALSE((std::is_convertible<int, result<X>>));
122 }
123
124 {
125 result<void> r( in_place_value );
126
127 BOOST_TEST( r.has_value() );
128 BOOST_TEST( !r.has_error() );
129 }
130
131 return boost::report_errors();
132}
133

source code of boost/libs/system/test/result_value_construct.cpp