沒想通的關於複製建構函式C++程式碼: A obj=func()
阿新 • • 發佈:2018-12-10
class A { public: A(int x=0):i(x) { cout << "Normal Contructor: " << i << endl; } ~A() { cout << "Destructor: " << i << endl; } A(const A & x) { cout << "Copy Constructor: " << i << endl; } A& operator=(const A & x) { cout << "Operator = " << endl; return *this; } int i; }; A fun () { A t(2); return t; }
int main() { A a(1); A b = fun(); //fun(); cout << "end of program" << endl; return 0; }
上面main()函式執行後的輸出為:
Normal Contructor: 1
Normal Contructor: 2
end of program
Destructor: 2
Destructor: 1
int main() { A a(1); //A b = fun(); fun(); cout << "end of program" << endl; return 0; }
輸出為:
Normal Contructor: 1
Normal Contructor: 2
Destructor: 2
end of program
Destructor: 1