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// template <class T> 1301afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant// constexpr 1401afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant// optional<typename decay<T>::type> 1501afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant// make_optional(T&& v); 1601afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant 170cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow#include <experimental/optional> 1801afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant#include <string> 1901afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant#include <memory> 2001afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant#include <cassert> 2101afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant 2201afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnantint main() 2301afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant{ 2401afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant#if _LIBCPP_STD_VER > 11 250cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow using std::experimental::optional; 260cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow using std::experimental::make_optional; 270cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow 2801afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant { 290cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow optional<int> opt = make_optional(2); 3001afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant assert(*opt == 2); 3101afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant } 3201afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant { 3301afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant std::string s("123"); 340cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow optional<std::string> opt = make_optional(s); 3501afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant assert(*opt == s); 3601afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant } 3701afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant { 3801afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant std::string s("123"); 390cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow optional<std::string> opt = make_optional(std::move(s)); 4001afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant assert(*opt == "123"); 4101afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant assert(s.empty()); 4201afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant } 4301afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant { 4401afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant std::unique_ptr<int> s(new int(3)); 450cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow optional<std::unique_ptr<int>> opt = make_optional(std::move(s)); 4601afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant assert(**opt == 3); 4701afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant assert(s == nullptr); 4801afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant } 4901afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant#endif // _LIBCPP_STD_VER > 11 5001afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant} 51