//===----------------------------------------------------------------------===// // // 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> // optional<T>& operator=(optional<T>&& rhs) // noexcept(is_nothrow_move_assignable<T>::value && // is_nothrow_move_constructible<T>::value); #include <experimental/optional> #include <type_traits> #include <cassert> #if _LIBCPP_STD_VER > 11 using std::experimental::optional; struct X { static bool throw_now; X() = default; X(X&&) { if (throw_now) throw 6; } X& operator=(X&&) noexcept { return *this; } }; struct Y {}; bool X::throw_now = false; #endif // _LIBCPP_STD_VER > 11 int main() { #if _LIBCPP_STD_VER > 11 { static_assert(std::is_nothrow_move_assignable<optional<int>>::value, ""); optional<int> opt; constexpr optional<int> opt2; opt = std::move(opt2); static_assert(static_cast<bool>(opt2) == false, ""); assert(static_cast<bool>(opt) == static_cast<bool>(opt2)); } { optional<int> opt; constexpr optional<int> opt2(2); opt = std::move(opt2); static_assert(static_cast<bool>(opt2) == true, ""); static_assert(*opt2 == 2, ""); assert(static_cast<bool>(opt) == static_cast<bool>(opt2)); assert(*opt == *opt2); } { optional<int> opt(3); constexpr optional<int> opt2; opt = std::move(opt2); static_assert(static_cast<bool>(opt2) == false, ""); assert(static_cast<bool>(opt) == static_cast<bool>(opt2)); } { optional<int> opt(3); constexpr optional<int> opt2(2); opt = std::move(opt2); static_assert(static_cast<bool>(opt2) == true, ""); static_assert(*opt2 == 2, ""); assert(static_cast<bool>(opt) == static_cast<bool>(opt2)); assert(*opt == *opt2); } { static_assert(!std::is_nothrow_move_assignable<optional<X>>::value, ""); optional<X> opt; optional<X> opt2(X{}); assert(static_cast<bool>(opt2) == true); try { X::throw_now = true; opt = std::move(opt2); assert(false); } catch (int i) { assert(i == 6); assert(static_cast<bool>(opt) == false); } } { static_assert(std::is_nothrow_move_assignable<optional<Y>>::value, ""); } #endif // _LIBCPP_STD_VER > 11 }