/* * Copyright (c) Facebook, Inc. and its affiliates. * * This source code is licensed under the MIT license found in the * LICENSE file in the root directory of this source tree. */ namespace temporaries { template struct UniquePtr { X* x_; ~UniquePtr() { if (x_) { delete x_; } } UniquePtr(X* y) { x_ = y; } UniquePtr(UniquePtr& p) = delete; // no copy constructor UniquePtr(UniquePtr&& p) { x_ = p.get(); p.x_ = nullptr; } X* get() const { return x_; } X& operator*() const { return *get(); } X* operator->() const { return get(); } }; struct A { int s_; ~A() {} A() { A(42); } A(int s) { s_ = s; } A(A& a) { s_ = a.s_; } }; UniquePtr mk_UniquePtr_A() { return UniquePtr(new A); } int call_mk_UniquePtr_A_deref_bad() { A* a = mk_UniquePtr_A().get(); // temporary unique_ptr returned by // `mk_UniquePtr_A` is destroyed at the end // of the statement return a->s_; } int call_mk_UniquePtr_A_ok() { const UniquePtr& local = mk_UniquePtr_A(); // ok, as ownership of a temporary unique_ptr is passed // to `local` return local->s_; } int call_mk_UniquePtr_A_copy_object_ok() { A a = *mk_UniquePtr_A().get(); // ok, as value is copied before temporary // unique_prt is destroyed return a.s_; } void temporary_in_ternary_ok() { while (true) { int x = true ? 0 : A(4).s_; } } void temporary_in_condition_ok() { while (true && A(4).s_ && true) {} } void call_mk_UniquePtr_A_get_field_ok() { int x = A().s_; } int FN_bind_temporary_to_const_bad() { A* a_ptr; { const UniquePtr& local = mk_UniquePtr_A(); a_ptr = local.get(); } return a_ptr->s_; } } // namespace temporaries