copy.pass.cpp (2508B)
1 //===----------------------------------------------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is dual licensed under the MIT and the University of Illinois Open 6 // Source Licenses. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 // UNSUPPORTED: c++98, c++03, c++11, c++14 11 // <optional> 12 13 // optional<T>& operator=(const optional<T>& rhs); // constexpr in C++20 14 15 #include <optional> 16 #include <type_traits> 17 #include <cassert> 18 19 #include "test_macros.h" 20 #include "archetypes.hpp" 21 22 using std::optional; 23 24 struct X 25 { 26 static bool throw_now; 27 28 X() = default; 29 X(const X&) 30 { 31 if (throw_now) 32 TEST_THROW(6); 33 } 34 }; 35 36 bool X::throw_now = false; 37 38 template <class Tp> 39 constexpr 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> 46 constexpr 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 52 int main() 53 { 54 { 55 using O = optional<int>; 56 #if TEST_STD_VER > 17 57 LIBCPP_STATIC_ASSERT(assign_empty(O{42}), ""); 58 LIBCPP_STATIC_ASSERT(assign_value(O{42}), ""); 59 #endif 60 assert(assign_empty(O{42})); 61 assert(assign_value(O{42})); 62 } 63 { 64 using O = optional<TrivialTestTypes::TestType>; 65 #if TEST_STD_VER > 17 66 LIBCPP_STATIC_ASSERT(assign_empty(O{42}), ""); 67 LIBCPP_STATIC_ASSERT(assign_value(O{42}), ""); 68 #endif 69 assert(assign_empty(O{42})); 70 assert(assign_value(O{42})); 71 } 72 { 73 using O = optional<TestTypes::TestType>; 74 assert(assign_empty(O{42})); 75 assert(assign_value(O{42})); 76 } 77 { 78 using T = TestTypes::TestType; 79 T::reset(); 80 optional<T> opt(3); 81 const optional<T> opt2; 82 assert(T::alive == 1); 83 opt = opt2; 84 assert(T::alive == 0); 85 assert(!opt2.has_value()); 86 assert(!opt.has_value()); 87 } 88 #ifndef TEST_HAS_NO_EXCEPTIONS 89 { 90 optional<X> opt; 91 optional<X> opt2(X{}); 92 assert(static_cast<bool>(opt2) == true); 93 try 94 { 95 X::throw_now = true; 96 opt = opt2; 97 assert(false); 98 } 99 catch (int i) 100 { 101 assert(i == 6); 102 assert(static_cast<bool>(opt) == false); 103 } 104 } 105 #endif 106 }