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 #include <boost/variant2/variant.hpp>
10
11 using namespace boost::variant2;
12
13 struct X
14 {
15 int v;
16 X() = default;
XX17 constexpr X( int v ): v( v ) {}
operator intX18 constexpr operator int() const { return v; }
19 };
20
21 struct Y
22 {
23 int v;
YY24 constexpr Y(): v() {}
YY25 constexpr Y( int v ): v( v ) {}
operator intY26 constexpr operator int() const { return v; }
27 };
28
29 enum E
30 {
31 v
32 };
33
34 #define STATIC_ASSERT(...) static_assert(__VA_ARGS__, #__VA_ARGS__)
35
test(A const & a)36 template<class V, class T, class A> constexpr A test( A const& a )
37 {
38 V v;
39
40 v = a;
41
42 return get<T>(v);
43 }
44
main()45 int main()
46 {
47 {
48 constexpr auto w = test<variant<int>, int>( 1 );
49 STATIC_ASSERT( w == 1 );
50 }
51
52 {
53 constexpr auto w = test<variant<X>, X>( 1 );
54 STATIC_ASSERT( w == 1 );
55 }
56
57 #if defined( BOOST_LIBSTDCXX_VERSION ) && BOOST_LIBSTDCXX_VERSION < 50000
58 #else
59
60 {
61 constexpr auto w = test<variant<Y>, Y>( 1 );
62 STATIC_ASSERT( w == 1 );
63 }
64
65 #endif
66
67 {
68 constexpr auto w = test<variant<int, float>, int>( 1 );
69 STATIC_ASSERT( w == 1 );
70 }
71
72 {
73 constexpr auto w = test<variant<int, float>, float>( 3.0f );
74 STATIC_ASSERT( w == 3.0f );
75 }
76
77 {
78 constexpr auto w = test<variant<int, int, float>, float>( 3.0f );
79 STATIC_ASSERT( w == 3.0f );
80 }
81
82 {
83 constexpr auto w = test<variant<E, E, X>, X>( 1 );
84 STATIC_ASSERT( w == 1 );
85 }
86
87 {
88 constexpr auto w = test<variant<int, int, float, float, X>, X>( X(1) );
89 STATIC_ASSERT( w == 1 );
90 }
91
92 #if defined( BOOST_LIBSTDCXX_VERSION ) && BOOST_LIBSTDCXX_VERSION < 50000
93 #else
94
95 {
96 constexpr auto w = test<variant<E, E, Y>, Y>( 1 );
97 STATIC_ASSERT( w == 1 );
98 }
99
100 {
101 constexpr auto w = test<variant<int, int, float, float, Y>, Y>( Y(1) );
102 STATIC_ASSERT( w == 1 );
103 }
104
105 #endif
106 }
107