function’s inherited default parameter value(Effective C++)

Never redefine an inherited default parameter value, because default parameter values are statically bound, while virtual functions — the only functions you should be overriding — are dynamically bound.

1#include<iostream>

2#include<string>

3usingnamespacestd;

4

5classShape

6{

7public:

8virtualvoiddraw(conststrings="Red")const

9{

10cout<<s<<"in shape"<<endl;

11}

12};

13

14classCircle :publicShape

15{

16public:

17virtualvoiddraw(conststrings="Blue")const

18{

19cout<<s<<"in circle"<<endl;

20}

21};

22

23intmain()

24{

25Shape*s=newCircle();

26s->draw();

27cin.get();

28return0;

29}

原文链接: https://www.cnblogs.com/zhtf2014/archive/2011/04/03/2004258.html

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