1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 // UNSUPPORTED: c++03, c++11, c++14 10 // <optional> 11 12 // constexpr optional<T>& operator=(const optional<T>& rhs); 13 14 #include <optional> 15 #include <type_traits> 16 #include <cassert> 17 18 #include "test_macros.h" 19 #include "archetypes.h" 20 21 using std::optional; 22 23 struct X 24 { 25 static bool throw_now; 26 27 X() = default; XX28 X(const X&) 29 { 30 if (throw_now) 31 TEST_THROW(6); 32 } 33 X& operator=(X const&) = default; 34 }; 35 36 bool X::throw_now = false; 37 38 template <class Tp> assign_empty(optional<Tp> && lhs)39constexpr bool assign_empty(optional<Tp>&& lhs) { 40 const optional<Tp> rhs; 41 lhs = rhs; 42 return !lhs.has_value() && !rhs.has_value(); 43 } 44 45 template <class Tp> assign_value(optional<Tp> && lhs)46constexpr bool assign_value(optional<Tp>&& lhs) { 47 const optional<Tp> rhs(101); 48 lhs = rhs; 49 return lhs.has_value() && rhs.has_value() && *lhs == *rhs; 50 } 51 main(int,char **)52int main(int, char**) 53 { 54 { 55 using O = optional<int>; 56 static_assert(assign_empty(O{42})); 57 static_assert(assign_value(O{42})); 58 assert(assign_empty(O{42})); 59 assert(assign_value(O{42})); 60 } 61 { 62 using O = optional<TrivialTestTypes::TestType>; 63 static_assert(assign_empty(O{42})); 64 static_assert(assign_value(O{42})); 65 assert(assign_empty(O{42})); 66 assert(assign_value(O{42})); 67 } 68 { 69 using O = optional<TestTypes::TestType>; 70 assert(assign_empty(O{42})); 71 assert(assign_value(O{42})); 72 } 73 { 74 using T = TestTypes::TestType; 75 T::reset(); 76 optional<T> opt(3); 77 const optional<T> opt2; 78 assert(T::alive == 1); 79 opt = opt2; 80 assert(T::alive == 0); 81 assert(!opt2.has_value()); 82 assert(!opt.has_value()); 83 } 84 #ifndef TEST_HAS_NO_EXCEPTIONS 85 { 86 optional<X> opt; 87 optional<X> opt2(X{}); 88 assert(static_cast<bool>(opt2) == true); 89 try 90 { 91 X::throw_now = true; 92 opt = opt2; 93 assert(false); 94 } 95 catch (int i) 96 { 97 assert(i == 6); 98 assert(static_cast<bool>(opt) == false); 99 } 100 } 101 #endif 102 103 return 0; 104 } 105