// // 3.5.move.semantics.cpp // modern c++ tutorial // // created by changkun at changkun.de // https://github.com/changkun/modern-cpp-tutorial // #include class A { public: int *pointer; A():pointer(new int(1)) { std::cout << "construct" << pointer << std::endl; } A(A& a):pointer(new int(*a.pointer)) { std::cout << "copy" << pointer << std::endl; } // meaningless object copy A(A&& a):pointer(a.pointer) { a.pointer = nullptr; std::cout << "move" << pointer << std::endl; } ~A(){ std::cout << "destruct" << pointer << std::endl; delete pointer; } }; // avoid compiler optimization A return_rvalue(bool test) { A a,b; if(test) return a; // equal to static_cast(a); else return b; // equal to static_cast(b); } int main() { A obj = return_rvalue(false); std::cout << "obj:" << std::endl; std::cout << obj.pointer << std::endl; std::cout << *obj.pointer << std::endl; return 0; }