Temporary object reference binding

A temporary object can only be bound with a constant reference. In this case, only constant functions can be called for constant reference.

However, you can directly call member functions on a temporary object (if there are non-constant functions and constant functions, the call of non-constant functions is preferred ).

1. # Include <stdio. h>
2. # Include <iostream>
3. Using namespace STD;
5. Class {
6. Public:
7. Virtual void func (INT data) {printf ("A1: % d/N", data );}
8. Virtual void func (INT data) const {printf ("A2: % d/N", data );}
9. };
11. Void func (const A & T)
12. {
13. T. func (10 );
14. Cout <"func is called! "<Endl;
15. }
16. A test ()
17. {
18. Return ();
19. }
21. Int main ()
22. {
23. // A & A = a (); // error, a () returns a temporary object and can only be bound with a constant reference.
24. Const A & A = a (); // seccessful
25. A. func (20); // call a constant function
26. Func (());
27. A (). func (1); // call a very large number of functions (if any)
28. Test (). func (100); // call a very large number of functions (if any)
30. Return 0;
31. }