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 // constexpr variant() noexcept(see below); 18 19 #include <cassert> 20 #include <type_traits> 21 #include <variant> 22 23 #include "test_macros.h" 24 #include "variant_test_helpers.hpp" 25 26 struct NonDefaultConstructible { 27 NonDefaultConstructible(int) {} 28 }; 29 30 struct NotNoexcept { 31 NotNoexcept() noexcept(false) {} 32 }; 33 34 #ifndef TEST_HAS_NO_EXCEPTIONS 35 struct DefaultCtorThrows { 36 DefaultCtorThrows() { throw 42; } 37 }; 38 #endif 39 40 void test_default_ctor_sfinae() { 41 { 42 using V = std::variant<std::monostate, int>; 43 static_assert(std::is_default_constructible<V>::value, ""); 44 } 45 { 46 using V = std::variant<NonDefaultConstructible, int>; 47 static_assert(!std::is_default_constructible<V>::value, ""); 48 } 49 #if !defined(TEST_VARIANT_HAS_NO_REFERENCES) 50 { 51 using V = std::variant<int &, int>; 52 static_assert(!std::is_default_constructible<V>::value, ""); 53 } 54 #endif 55 } 56 57 void test_default_ctor_noexcept() { 58 { 59 using V = std::variant<int>; 60 static_assert(std::is_nothrow_default_constructible<V>::value, ""); 61 } 62 { 63 using V = std::variant<NotNoexcept>; 64 static_assert(!std::is_nothrow_default_constructible<V>::value, ""); 65 } 66 } 67 68 void test_default_ctor_throws() { 69 #ifndef TEST_HAS_NO_EXCEPTIONS 70 using V = std::variant<DefaultCtorThrows, int>; 71 try { 72 V v; 73 assert(false); 74 } catch (const int &ex) { 75 assert(ex == 42); 76 } catch (...) { 77 assert(false); 78 } 79 #endif 80 } 81 82 void test_default_ctor_basic() { 83 { 84 std::variant<int> v; 85 assert(v.index() == 0); 86 assert(std::get<0>(v) == 0); 87 } 88 { 89 std::variant<int, long> v; 90 assert(v.index() == 0); 91 assert(std::get<0>(v) == 0); 92 } 93 { 94 using V = std::variant<int, long>; 95 constexpr V v; 96 static_assert(v.index() == 0, ""); 97 static_assert(std::get<0>(v) == 0, ""); 98 } 99 { 100 using V = std::variant<int, long>; 101 constexpr V v; 102 static_assert(v.index() == 0, ""); 103 static_assert(std::get<0>(v) == 0, ""); 104 } 105 } 106 107 int main() { 108 test_default_ctor_basic(); 109 test_default_ctor_sfinae(); 110 test_default_ctor_noexcept(); 111 test_default_ctor_throws(); 112 } 113
