1
2// Copyright 2017 Peter Dimov.
3//
4// Distributed under the Boost Software License, Version 1.0.
5//
6// See accompanying file LICENSE_1_0.txt or copy at
7// http://www.boost.org/LICENSE_1_0.txt
8
9#if defined(_MSC_VER)
10# pragma warning( disable: 4702 ) // unreachable code
11#endif
12
13#include <boost/variant2/variant.hpp>
14#include <boost/core/lightweight_test.hpp>
15#include <boost/core/lightweight_test_trait.hpp>
16#include <type_traits>
17#include <utility>
18#include <string>
19
20using namespace boost::variant2;
21
22#define STATIC_ASSERT(...) static_assert(__VA_ARGS__, #__VA_ARGS__)
23
24struct X1
25{
26 int v;
27
28 X1(): v(0) {}
29 explicit X1(int v): v(v) {}
30 X1(X1 const& r): v(r.v) {}
31 X1(X1&& r): v(r.v) {}
32 X1& operator=( X1 const& r ) { v = r.v; return *this; }
33 X1& operator=( X1&& r ) { v = r.v; return *this; }
34};
35
36inline bool operator==( X1 const& a, X1 const& b ) { return a.v == b.v; }
37
38STATIC_ASSERT( !std::is_nothrow_default_constructible<X1>::value );
39STATIC_ASSERT( !std::is_nothrow_copy_constructible<X1>::value );
40STATIC_ASSERT( !std::is_nothrow_move_constructible<X1>::value );
41STATIC_ASSERT( !std::is_nothrow_copy_assignable<X1>::value );
42STATIC_ASSERT( !std::is_nothrow_move_assignable<X1>::value );
43
44struct X2
45{
46 int v;
47
48 X2(): v(0) {}
49 explicit X2(int v): v(v) {}
50 X2(X2 const& r): v(r.v) {}
51 X2(X2&& r): v(r.v) {}
52 X2& operator=( X2 const& r ) { v = r.v; return *this; }
53 X2& operator=( X2&& r ) { v = r.v; return *this; }
54};
55
56inline bool operator==( X2 const& a, X2 const& b ) { return a.v == b.v; }
57
58STATIC_ASSERT( !std::is_nothrow_default_constructible<X2>::value );
59STATIC_ASSERT( !std::is_nothrow_copy_constructible<X2>::value );
60STATIC_ASSERT( !std::is_nothrow_move_constructible<X2>::value );
61STATIC_ASSERT( !std::is_nothrow_copy_assignable<X2>::value );
62STATIC_ASSERT( !std::is_nothrow_move_assignable<X2>::value );
63
64int main()
65{
66 {
67 variant<int, float> v1( 1 );
68
69 variant<int> v2 = v1.subset<int>();
70
71 BOOST_TEST( holds_alternative<int>( v2 ) );
72 BOOST_TEST_EQ( get<int>( v1 ), get<int>( v2 ) );
73
74 BOOST_TEST_THROWS( v1.subset<float>(), bad_variant_access );
75
76 variant<int> v3 = std::move(v1).subset<int>();
77
78 BOOST_TEST( holds_alternative<int>( v3 ) );
79 BOOST_TEST_EQ( get<int>( v2 ), get<int>( v3 ) );
80
81 BOOST_TEST_THROWS( std::move(v1).subset<float>(), bad_variant_access );
82 }
83
84 {
85 variant<int, float> const v1( 1 );
86
87 variant<int> v2 = v1.subset<int>();
88
89 BOOST_TEST( holds_alternative<int>( v2 ) );
90 BOOST_TEST_EQ( get<int>( v1 ), get<int>( v2 ) );
91
92 BOOST_TEST_THROWS( v1.subset<float>(), bad_variant_access );
93
94 variant<int> v3 = std::move(v1).subset<int>();
95
96 BOOST_TEST( holds_alternative<int>( v3 ) );
97 BOOST_TEST_EQ( get<int>( v2 ), get<int>( v3 ) );
98
99 BOOST_TEST_THROWS( std::move(v1).subset<float>(), bad_variant_access );
100 }
101
102 {
103 variant<int, float> v1( 1 );
104
105 variant<int, float> v2 = v1.subset<int, float>();
106
107 BOOST_TEST( holds_alternative<int>( v2 ) );
108 BOOST_TEST_EQ( get<int>( v1 ), get<int>( v2 ) );
109
110 variant<int, float> v3 = std::move(v1).subset<int, float>();
111
112 BOOST_TEST( holds_alternative<int>( v3 ) );
113 BOOST_TEST_EQ( get<int>( v2 ), get<int>( v3 ) );
114 }
115
116 {
117 variant<int, float> v1( 1 );
118
119 variant<float, int> v2 = v1.subset<float, int>();
120
121 BOOST_TEST( holds_alternative<int>( v2 ) );
122 BOOST_TEST_EQ( get<int>( v1 ), get<int>( v2 ) );
123
124 variant<float, int> v3 = std::move(v1).subset<float, int>();
125
126 BOOST_TEST( holds_alternative<int>( v3 ) );
127 BOOST_TEST_EQ( get<int>( v2 ), get<int>( v3 ) );
128 }
129
130 {
131 variant<int, float, std::string> v1( "s1" );
132
133 variant<int, std::string> v2 = v1.subset<int, std::string>();
134
135 BOOST_TEST( holds_alternative<std::string>( v2 ) );
136 BOOST_TEST_EQ( get<std::string>( v1 ), get<std::string>( v2 ) );
137
138 variant<float, std::string> v3 = std::move(v1).subset<float, std::string>();
139
140 BOOST_TEST( holds_alternative<std::string>( v3 ) );
141 BOOST_TEST_EQ( get<std::string>( v2 ), get<std::string>( v3 ) );
142 }
143
144 {
145 variant<int, int, float, float, X1, X2> v1{ X1{1} };
146
147 variant<X1, X2> v2 = v1.subset<X1, X2>();
148
149 BOOST_TEST( holds_alternative<X1>( v2 ) );
150 BOOST_TEST_EQ( get<X1>( v1 ).v, get<X1>( v2 ).v );
151
152 variant<X1, X2> v3 = std::move( v1 ).subset<X1, X2>();
153
154 BOOST_TEST( holds_alternative<X1>( v3 ) );
155 BOOST_TEST_EQ( get<X1>( v2 ).v, get<X1>( v3 ).v );
156 }
157
158 return boost::report_errors();
159}
160

source code of boost/libs/variant2/test/variant_subset.cpp