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 U> constexpr T optional<T>::value_or(U&& v) const&; 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 Clow 2201afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnantstruct Y 2301afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant{ 2401afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant int i_; 2501afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant 2601afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant constexpr Y(int i) : i_(i) {} 2701afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant}; 2801afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant 2901afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnantstruct X 3001afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant{ 3101afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant int i_; 3201afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant 3301afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant constexpr X(int i) : i_(i) {} 3401afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant constexpr X(const Y& y) : i_(y.i_) {} 3501afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant constexpr X(Y&& y) : i_(y.i_+1) {} 3601afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant friend constexpr bool operator==(const X& x, const X& y) 3701afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant {return x.i_ == y.i_;} 3801afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant}; 3901afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant 4001afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant#endif // _LIBCPP_STD_VER > 11 4101afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant 4201afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnantint main() 4301afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant{ 4401afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant#if _LIBCPP_STD_VER > 11 4501afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant { 460cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow constexpr optional<X> opt(2); 4701afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant constexpr Y y(3); 4801afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant static_assert(opt.value_or(y) == 2, ""); 4901afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant } 5001afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant { 510cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow constexpr optional<X> opt(2); 5201afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant static_assert(opt.value_or(Y(3)) == 2, ""); 5301afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant } 5401afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant { 550cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow constexpr optional<X> opt; 5601afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant constexpr Y y(3); 5701afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant static_assert(opt.value_or(y) == 3, ""); 5801afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant } 5901afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant { 600cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow constexpr optional<X> opt; 6101afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant static_assert(opt.value_or(Y(3)) == 4, ""); 6201afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant } 6301afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant { 640cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow const optional<X> opt(2); 6501afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant const Y y(3); 6601afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant assert(opt.value_or(y) == 2); 6701afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant } 6801afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant { 690cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow const optional<X> opt(2); 7001afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant assert(opt.value_or(Y(3)) == 2); 7101afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant } 7201afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant { 730cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow const optional<X> opt; 7401afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant const Y y(3); 7501afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant assert(opt.value_or(y) == 3); 7601afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant } 7701afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant { 780cdbe6048173c1f05628dbc85430acf191a3e173Marshall Clow const optional<X> opt; 7901afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant assert(opt.value_or(Y(3)) == 4); 8001afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant } 8101afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant#endif // _LIBCPP_STD_VER > 11 8201afa5c6e407e985d9643707d7b7ab1384bd9317Howard Hinnant} 83