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// <optional> 11 12// struct in_place_t{}; 13// constexpr in_place_t in_place{}; 14 15#include <experimental/optional> 16#include <type_traits> 17 18#if _LIBCPP_STD_VER > 11 19 20using std::experimental::optional; 21using std::experimental::in_place_t; 22using std::experimental::in_place; 23 24constexpr 25int 26test(const in_place_t&) 27{ 28 return 3; 29} 30 31#endif 32 33int main() 34{ 35#if _LIBCPP_STD_VER > 11 36 37 static_assert((std::is_class<in_place_t>::value), ""); 38 static_assert((std::is_empty<in_place_t>::value), ""); 39 40 static_assert(test(in_place) == 3, ""); 41#endif 42} 43