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=(nullopt_t) noexcept; 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 using std::nullopt_t; 24 using std::nullopt; 25 26 int main() 27 { 28 { 29 optional<int> opt; 30 static_assert(noexcept(opt = nullopt) == true, ""); 31 opt = nullopt; 32 assert(static_cast<bool>(opt) == false); 33 } 34 { 35 optional<int> opt(3); 36 opt = nullopt; 37 assert(static_cast<bool>(opt) == false); 38 } 39 using TT = TestTypes::TestType; 40 TT::reset(); 41 { 42 optional<TT> opt; 43 static_assert(noexcept(opt = nullopt) == true, ""); 44 assert(TT::destroyed == 0); 45 opt = nullopt; 46 assert(TT::constructed == 0); 47 assert(TT::alive == 0); 48 assert(TT::destroyed == 0); 49 assert(static_cast<bool>(opt) == false); 50 } 51 assert(TT::alive == 0); 52 assert(TT::destroyed == 0); 53 TT::reset(); 54 { 55 optional<TT> opt(42); 56 assert(TT::destroyed == 0); 57 TT::reset_constructors(); 58 opt = nullopt; 59 assert(TT::constructed == 0); 60 assert(TT::alive == 0); 61 assert(TT::destroyed == 1); 62 assert(static_cast<bool>(opt) == false); 63 } 64 assert(TT::alive == 0); 65 assert(TT::destroyed == 1); 66 TT::reset(); 67 } 68
