//===----------------------------------------------------------------------===// // // The LLVM Compiler Infrastructure // // This file is dual licensed under the MIT and the University of Illinois Open // Source Licenses. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // <optional> // constexpr optional() noexcept; #include <experimental/optional> #include <type_traits> #include <cassert> #if _LIBCPP_STD_VER > 11 using std::experimental::optional; template <class Opt> void test_constexpr() { static_assert(std::is_nothrow_default_constructible<Opt>::value, ""); constexpr Opt opt; static_assert(static_cast<bool>(opt) == false, ""); struct test_constexpr_ctor : public Opt { constexpr test_constexpr_ctor() {} }; } template <class Opt> void test() { static_assert(std::is_nothrow_default_constructible<Opt>::value, ""); Opt opt; assert(static_cast<bool>(opt) == false); struct test_constexpr_ctor : public Opt { constexpr test_constexpr_ctor() {} }; } struct X { X(); }; #endif // _LIBCPP_STD_VER > 11 int main() { #if _LIBCPP_STD_VER > 11 test_constexpr<optional<int>>(); test_constexpr<optional<int*>>(); test<optional<X>>(); #endif // _LIBCPP_STD_VER > 11 }