101afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant//===----------------------------------------------------------------------===// 201afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant// 301afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant// The LLVM Compiler Infrastructure 401afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant// 501afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant// This file is dual licensed under the MIT and the University of Illinois Open 601afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant// Source Licenses. See LICENSE.TXT for details. 701afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant// 801afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant//===----------------------------------------------------------------------===// 901afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant 1001afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant// <optional> 1101afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant 1201afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant// optional<T>& operator=(nullopt_t) noexcept; 1301afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant 140cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow#include <experimental/optional> 1501afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant#include <type_traits> 1601afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant#include <cassert> 1701afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant 1801afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant#if _LIBCPP_STD_VER > 11 1901afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant 200cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clowusing std::experimental::optional; 210cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clowusing std::experimental::nullopt_t; 220cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clowusing std::experimental::nullopt; 230cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow 2401afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnantstruct X 2501afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant{ 2601afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant static bool dtor_called; 2701afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant ~X() {dtor_called = true;} 2801afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant}; 2901afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant 3001afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnantbool X::dtor_called = false; 3101afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant 3201afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant#endif // _LIBCPP_STD_VER > 11 3301afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant 3401afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnantint main() 3501afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant{ 3601afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant#if _LIBCPP_STD_VER > 11 3701afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant { 380cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow optional<int> opt; 390cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow static_assert(noexcept(opt = nullopt) == true, ""); 400cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow opt = nullopt; 4101afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant assert(static_cast<bool>(opt) == false); 4201afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant } 4301afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant { 440cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow optional<int> opt(3); 450cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow opt = nullopt; 4601afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant assert(static_cast<bool>(opt) == false); 4701afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant } 4801afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant { 490cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow optional<X> opt; 500cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow static_assert(noexcept(opt = nullopt) == true, ""); 5101afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant assert(X::dtor_called == false); 520cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow opt = nullopt; 5301afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant assert(X::dtor_called == false); 5401afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant assert(static_cast<bool>(opt) == false); 5501afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant } 5601afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant { 5701afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant X x; 5801afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant { 590cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow optional<X> opt(x); 6001afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant assert(X::dtor_called == false); 610cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow opt = nullopt; 6201afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant assert(X::dtor_called == true); 6301afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant assert(static_cast<bool>(opt) == false); 6401afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant } 6501afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant } 6601afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant#endif // _LIBCPP_STD_VER > 11 6701afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant} 68