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 // UNSUPPORTED: c++98, c++03, c++11 11 // <optional> 12 13 // struct in_place_t{}; 14 // constexpr in_place_t in_place{}; 15 16 #include <experimental/optional> 17 #include <type_traits> 18 19 using std::experimental::optional; 20 using std::experimental::in_place_t; 21 using std::experimental::in_place; 22 23 constexpr 24 int test(const in_place_t &)25test(const in_place_t&) 26 { 27 return 3; 28 } 29 main()30int main() 31 { 32 static_assert((std::is_class<in_place_t>::value), ""); 33 static_assert((std::is_empty<in_place_t>::value), ""); 34 35 static_assert(test(in_place) == 3, ""); 36 } 37