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
|
// Copyright 2017 Peter Dimov.
//
// 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
#if defined(_MSC_VER)
# pragma warning( disable: 4702 ) // unreachable code
#endif
#include <boost/variant2/variant.hpp>
#include <boost/core/lightweight_test.hpp>
#include <boost/core/lightweight_test_trait.hpp>
#include <type_traits>
#include <utility>
#include <string>
using namespace boost::variant2;
#define STATIC_ASSERT(...) static_assert(__VA_ARGS__, #__VA_ARGS__)
struct X1
{
int v;
X1(): v(0) {}
explicit X1(int v): v(v) {}
X1(X1 const& r): v(r.v) {}
X1(X1&& r): v(r.v) {}
X1& operator=( X1 const& r ) { v = r.v; return *this; }
X1& operator=( X1&& r ) { v = r.v; return *this; }
};
inline bool operator==( X1 const& a, X1 const& b ) { return a.v == b.v; }
STATIC_ASSERT( !std::is_nothrow_default_constructible<X1>::value );
STATIC_ASSERT( !std::is_nothrow_copy_constructible<X1>::value );
STATIC_ASSERT( !std::is_nothrow_move_constructible<X1>::value );
STATIC_ASSERT( !std::is_nothrow_copy_assignable<X1>::value );
STATIC_ASSERT( !std::is_nothrow_move_assignable<X1>::value );
struct X2
{
int v;
X2(): v(0) {}
explicit X2(int v): v(v) {}
X2(X2 const& r): v(r.v) {}
X2(X2&& r): v(r.v) {}
X2& operator=( X2 const& r ) { v = r.v; return *this; }
X2& operator=( X2&& r ) { v = r.v; return *this; }
};
inline bool operator==( X2 const& a, X2 const& b ) { return a.v == b.v; }
STATIC_ASSERT( !std::is_nothrow_default_constructible<X2>::value );
STATIC_ASSERT( !std::is_nothrow_copy_constructible<X2>::value );
STATIC_ASSERT( !std::is_nothrow_move_constructible<X2>::value );
STATIC_ASSERT( !std::is_nothrow_copy_assignable<X2>::value );
STATIC_ASSERT( !std::is_nothrow_move_assignable<X2>::value );
int main()
{
{
variant<int, float> v1( 1 );
variant<int> v2 = v1.subset<int>();
BOOST_TEST( holds_alternative<int>( v2 ) );
BOOST_TEST_EQ( get<int>( v1 ), get<int>( v2 ) );
BOOST_TEST_THROWS( v1.subset<float>(), bad_variant_access );
variant<int> v3 = std::move(v1).subset<int>();
BOOST_TEST( holds_alternative<int>( v3 ) );
BOOST_TEST_EQ( get<int>( v2 ), get<int>( v3 ) );
BOOST_TEST_THROWS( std::move(v1).subset<float>(), bad_variant_access );
}
{
variant<int, float> const v1( 1 );
variant<int> v2 = v1.subset<int>();
BOOST_TEST( holds_alternative<int>( v2 ) );
BOOST_TEST_EQ( get<int>( v1 ), get<int>( v2 ) );
BOOST_TEST_THROWS( v1.subset<float>(), bad_variant_access );
variant<int> v3 = std::move(v1).subset<int>();
BOOST_TEST( holds_alternative<int>( v3 ) );
BOOST_TEST_EQ( get<int>( v2 ), get<int>( v3 ) );
BOOST_TEST_THROWS( std::move(v1).subset<float>(), bad_variant_access );
}
{
variant<int, float> v1( 1 );
variant<int, float> v2 = v1.subset<int, float>();
BOOST_TEST( holds_alternative<int>( v2 ) );
BOOST_TEST_EQ( get<int>( v1 ), get<int>( v2 ) );
variant<int, float> v3 = std::move(v1).subset<int, float>();
BOOST_TEST( holds_alternative<int>( v3 ) );
BOOST_TEST_EQ( get<int>( v2 ), get<int>( v3 ) );
}
{
variant<int, float> v1( 1 );
variant<float, int> v2 = v1.subset<float, int>();
BOOST_TEST( holds_alternative<int>( v2 ) );
BOOST_TEST_EQ( get<int>( v1 ), get<int>( v2 ) );
variant<float, int> v3 = std::move(v1).subset<float, int>();
BOOST_TEST( holds_alternative<int>( v3 ) );
BOOST_TEST_EQ( get<int>( v2 ), get<int>( v3 ) );
}
{
variant<int, float, std::string> v1( "s1" );
variant<int, std::string> v2 = v1.subset<int, std::string>();
BOOST_TEST( holds_alternative<std::string>( v2 ) );
BOOST_TEST_EQ( get<std::string>( v1 ), get<std::string>( v2 ) );
variant<float, std::string> v3 = std::move(v1).subset<float, std::string>();
BOOST_TEST( holds_alternative<std::string>( v3 ) );
BOOST_TEST_EQ( get<std::string>( v2 ), get<std::string>( v3 ) );
}
{
variant<int, int, float, float, X1, X2> v1{ X1{1} };
variant<X1, X2> v2 = v1.subset<X1, X2>();
BOOST_TEST( holds_alternative<X1>( v2 ) );
BOOST_TEST_EQ( get<X1>( v1 ).v, get<X1>( v2 ).v );
variant<X1, X2> v3 = std::move( v1 ).subset<X1, X2>();
BOOST_TEST( holds_alternative<X1>( v3 ) );
BOOST_TEST_EQ( get<X1>( v2 ).v, get<X1>( v3 ).v );
}
return boost::report_errors();
}
|
