//===----------------------------------------------------------------------===// // // 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> // void swap(optional&) // noexcept(is_nothrow_move_constructible<T>::value && // noexcept(swap(declval<T&>(), declval<T&>()))); #include <experimental/optional> #include <type_traits> #include <cassert> #if _LIBCPP_STD_VER > 11 using std::experimental::optional; class X { int i_; public: static unsigned dtor_called; X(int i) : i_(i) {} X(X&& x) = default; X& operator=(X&&) = default; ~X() {++dtor_called;} friend bool operator==(const X& x, const X& y) {return x.i_ == y.i_;} }; unsigned X::dtor_called = 0; class Y { int i_; public: static unsigned dtor_called; Y(int i) : i_(i) {} Y(Y&&) = default; ~Y() {++dtor_called;} friend constexpr bool operator==(const Y& x, const Y& y) {return x.i_ == y.i_;} friend void swap(Y& x, Y& y) {std::swap(x.i_, y.i_);} }; unsigned Y::dtor_called = 0; class Z { int i_; public: Z(int i) : i_(i) {} Z(Z&&) {throw 7;} friend constexpr bool operator==(const Z& x, const Z& y) {return x.i_ == y.i_;} friend void swap(Z& x, Z& y) {throw 6;} }; #endif // _LIBCPP_STD_VER > 11 int main() { #if _LIBCPP_STD_VER > 11 { optional<int> opt1; optional<int> opt2; static_assert(noexcept(opt1.swap(opt2)) == true, ""); assert(static_cast<bool>(opt1) == false); assert(static_cast<bool>(opt2) == false); opt1.swap(opt2); assert(static_cast<bool>(opt1) == false); assert(static_cast<bool>(opt2) == false); } { optional<int> opt1(1); optional<int> opt2; static_assert(noexcept(opt1.swap(opt2)) == true, ""); assert(static_cast<bool>(opt1) == true); assert(*opt1 == 1); assert(static_cast<bool>(opt2) == false); opt1.swap(opt2); assert(static_cast<bool>(opt1) == false); assert(static_cast<bool>(opt2) == true); assert(*opt2 == 1); } { optional<int> opt1; optional<int> opt2(2); static_assert(noexcept(opt1.swap(opt2)) == true, ""); assert(static_cast<bool>(opt1) == false); assert(static_cast<bool>(opt2) == true); assert(*opt2 == 2); opt1.swap(opt2); assert(static_cast<bool>(opt1) == true); assert(*opt1 == 2); assert(static_cast<bool>(opt2) == false); } { optional<int> opt1(1); optional<int> opt2(2); static_assert(noexcept(opt1.swap(opt2)) == true, ""); assert(static_cast<bool>(opt1) == true); assert(*opt1 == 1); assert(static_cast<bool>(opt2) == true); assert(*opt2 == 2); opt1.swap(opt2); assert(static_cast<bool>(opt1) == true); assert(*opt1 == 2); assert(static_cast<bool>(opt2) == true); assert(*opt2 == 1); } { optional<X> opt1; optional<X> opt2; static_assert(noexcept(opt1.swap(opt2)) == true, ""); assert(static_cast<bool>(opt1) == false); assert(static_cast<bool>(opt2) == false); opt1.swap(opt2); assert(static_cast<bool>(opt1) == false); assert(static_cast<bool>(opt2) == false); assert(X::dtor_called == 0); } { optional<X> opt1(1); optional<X> opt2; static_assert(noexcept(opt1.swap(opt2)) == true, ""); assert(static_cast<bool>(opt1) == true); assert(*opt1 == 1); assert(static_cast<bool>(opt2) == false); X::dtor_called = 0; opt1.swap(opt2); assert(X::dtor_called == 1); assert(static_cast<bool>(opt1) == false); assert(static_cast<bool>(opt2) == true); assert(*opt2 == 1); } { optional<X> opt1; optional<X> opt2(2); static_assert(noexcept(opt1.swap(opt2)) == true, ""); assert(static_cast<bool>(opt1) == false); assert(static_cast<bool>(opt2) == true); assert(*opt2 == 2); X::dtor_called = 0; opt1.swap(opt2); assert(X::dtor_called == 1); assert(static_cast<bool>(opt1) == true); assert(*opt1 == 2); assert(static_cast<bool>(opt2) == false); } { optional<X> opt1(1); optional<X> opt2(2); static_assert(noexcept(opt1.swap(opt2)) == true, ""); assert(static_cast<bool>(opt1) == true); assert(*opt1 == 1); assert(static_cast<bool>(opt2) == true); assert(*opt2 == 2); X::dtor_called = 0; opt1.swap(opt2); assert(X::dtor_called == 1); // from inside std::swap assert(static_cast<bool>(opt1) == true); assert(*opt1 == 2); assert(static_cast<bool>(opt2) == true); assert(*opt2 == 1); } { optional<Y> opt1; optional<Y> opt2; static_assert(noexcept(opt1.swap(opt2)) == false, ""); assert(static_cast<bool>(opt1) == false); assert(static_cast<bool>(opt2) == false); opt1.swap(opt2); assert(static_cast<bool>(opt1) == false); assert(static_cast<bool>(opt2) == false); assert(Y::dtor_called == 0); } { optional<Y> opt1(1); optional<Y> opt2; static_assert(noexcept(opt1.swap(opt2)) == false, ""); assert(static_cast<bool>(opt1) == true); assert(*opt1 == 1); assert(static_cast<bool>(opt2) == false); Y::dtor_called = 0; opt1.swap(opt2); assert(Y::dtor_called == 1); assert(static_cast<bool>(opt1) == false); assert(static_cast<bool>(opt2) == true); assert(*opt2 == 1); } { optional<Y> opt1; optional<Y> opt2(2); static_assert(noexcept(opt1.swap(opt2)) == false, ""); assert(static_cast<bool>(opt1) == false); assert(static_cast<bool>(opt2) == true); assert(*opt2 == 2); Y::dtor_called = 0; opt1.swap(opt2); assert(Y::dtor_called == 1); assert(static_cast<bool>(opt1) == true); assert(*opt1 == 2); assert(static_cast<bool>(opt2) == false); } { optional<Y> opt1(1); optional<Y> opt2(2); static_assert(noexcept(opt1.swap(opt2)) == false, ""); assert(static_cast<bool>(opt1) == true); assert(*opt1 == 1); assert(static_cast<bool>(opt2) == true); assert(*opt2 == 2); Y::dtor_called = 0; opt1.swap(opt2); assert(Y::dtor_called == 0); assert(static_cast<bool>(opt1) == true); assert(*opt1 == 2); assert(static_cast<bool>(opt2) == true); assert(*opt2 == 1); } { optional<Z> opt1; optional<Z> opt2; static_assert(noexcept(opt1.swap(opt2)) == false, ""); assert(static_cast<bool>(opt1) == false); assert(static_cast<bool>(opt2) == false); opt1.swap(opt2); assert(static_cast<bool>(opt1) == false); assert(static_cast<bool>(opt2) == false); } { optional<Z> opt1; opt1.emplace(1); optional<Z> opt2; static_assert(noexcept(opt1.swap(opt2)) == false, ""); assert(static_cast<bool>(opt1) == true); assert(*opt1 == 1); assert(static_cast<bool>(opt2) == false); try { opt1.swap(opt2); assert(false); } catch (int i) { assert(i == 7); } assert(static_cast<bool>(opt1) == true); assert(*opt1 == 1); assert(static_cast<bool>(opt2) == false); } { optional<Z> opt1; optional<Z> opt2; opt2.emplace(2); static_assert(noexcept(opt1.swap(opt2)) == false, ""); assert(static_cast<bool>(opt1) == false); assert(static_cast<bool>(opt2) == true); assert(*opt2 == 2); try { opt1.swap(opt2); assert(false); } catch (int i) { assert(i == 7); } assert(static_cast<bool>(opt1) == false); assert(static_cast<bool>(opt2) == true); assert(*opt2 == 2); } { optional<Z> opt1; opt1.emplace(1); optional<Z> opt2; opt2.emplace(2); static_assert(noexcept(opt1.swap(opt2)) == false, ""); assert(static_cast<bool>(opt1) == true); assert(*opt1 == 1); assert(static_cast<bool>(opt2) == true); assert(*opt2 == 2); try { opt1.swap(opt2); assert(false); } catch (int i) { assert(i == 6); } assert(static_cast<bool>(opt1) == true); assert(*opt1 == 1); assert(static_cast<bool>(opt2) == true); assert(*opt2 == 2); } #endif // _LIBCPP_STD_VER > 11 }