1 // -*- C++ -*- 2 //===----------------------------------------------------------------------===// 3 // 4 // The LLVM Compiler Infrastructure 5 // 6 // This file is dual licensed under the MIT and the University of Illinois Open 7 // Source Licenses. See LICENSE.TXT for details. 8 // 9 //===----------------------------------------------------------------------===// 10 11 // UNSUPPORTED: c++98, c++03, c++11, c++14 12 13 // <variant> 14 15 // template <class ...Types> class variant; 16 17 // template <class T> constexpr variant(T&&) noexcept(see below); 18 19 #include <cassert> 20 #include <string> 21 #include <type_traits> 22 #include <variant> 23 24 #include "test_convertible.hpp" 25 #include "test_macros.h" 26 #include "variant_test_helpers.hpp" 27 28 struct Dummy { 29 Dummy() = default; 30 }; 31 32 struct ThrowsT { 33 ThrowsT(int) noexcept(false) {} 34 }; 35 36 struct NoThrowT { 37 NoThrowT(int) noexcept(true) {} 38 }; 39 40 void test_T_ctor_noexcept() { 41 { 42 using V = std::variant<Dummy, NoThrowT>; 43 static_assert(std::is_nothrow_constructible<V, int>::value, ""); 44 } 45 { 46 using V = std::variant<Dummy, ThrowsT>; 47 static_assert(!std::is_nothrow_constructible<V, int>::value, ""); 48 } 49 } 50 51 void test_T_ctor_sfinae() { 52 { 53 using V = std::variant<long, unsigned>; 54 static_assert(!std::is_constructible<V, int>::value, "ambiguous"); 55 } 56 { 57 using V = std::variant<std::string, std::string>; 58 static_assert(!std::is_constructible<V, const char *>::value, "ambiguous"); 59 } 60 { 61 using V = std::variant<std::string, void *>; 62 static_assert(!std::is_constructible<V, int>::value, 63 "no matching constructor"); 64 } 65 #if !defined(TEST_VARIANT_HAS_NO_REFERENCES) 66 { 67 using V = std::variant<int, int &&>; 68 static_assert(!std::is_constructible<V, int>::value, "ambiguous"); 69 } 70 { 71 using V = std::variant<int, const int &>; 72 static_assert(!std::is_constructible<V, int>::value, "ambiguous"); 73 } 74 #endif 75 } 76 77 void test_T_ctor_basic() { 78 { 79 constexpr std::variant<int> v(42); 80 static_assert(v.index() == 0, ""); 81 static_assert(std::get<0>(v) == 42, ""); 82 } 83 { 84 constexpr std::variant<int, long> v(42l); 85 static_assert(v.index() == 1, ""); 86 static_assert(std::get<1>(v) == 42, ""); 87 } 88 #if !defined(TEST_VARIANT_HAS_NO_REFERENCES) 89 { 90 using V = std::variant<const int &, int &&, long>; 91 static_assert(std::is_convertible<int &, V>::value, "must be implicit"); 92 int x = 42; 93 V v(x); 94 assert(v.index() == 0); 95 assert(&std::get<0>(v) == &x); 96 } 97 { 98 using V = std::variant<const int &, int &&, long>; 99 static_assert(std::is_convertible<int, V>::value, "must be implicit"); 100 int x = 42; 101 V v(std::move(x)); 102 assert(v.index() == 1); 103 assert(&std::get<1>(v) == &x); 104 } 105 #endif 106 } 107 108 int main() { 109 test_T_ctor_basic(); 110 test_T_ctor_noexcept(); 111 test_T_ctor_sfinae(); 112 } 113
