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// class optional 1401afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant// { 1501afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant// public: 1601afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant// typedef T value_type; 1701afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant// ... 1801afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant 190cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow#include <experimental/optional> 2001afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant#include <type_traits> 2101afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant 2201afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant#if _LIBCPP_STD_VER > 11 2301afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant 240cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clowusing std::experimental::optional; 250cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow 2601afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnanttemplate <class Opt, class T> 2701afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnantvoid 2801afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnanttest() 2901afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant{ 3001afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant static_assert(std::is_same<typename Opt::value_type, T>::value, ""); 3101afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant} 3201afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant 3301afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant#endif // _LIBCPP_STD_VER > 11 3401afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant 3501afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnantint main() 3601afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant{ 3701afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant#if _LIBCPP_STD_VER > 11 380cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow test<optional<int>, int>(); 390cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow test<optional<const int>, const int>(); 400cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow test<optional<double>, double>(); 410cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow test<optional<const double>, const double>(); 4201afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant#endif // _LIBCPP_STD_VER > 11 4301afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant} 44