C Pointer-to-Function 与 C++ Pointer-to-MemberFunction 的区别

 1 #include <functional>
 2 #include <iostream>
 3 #include <algorithm>
 4 
 5 
 6 using namespace std;
 7 
 8 void my(int arg);
 9 
10 class MyClass
11 {
12 public:
13     void my(int arg) { cout << arg << endl; }
14 };
15 
16 // 方法1,2
17 
18 typedef void func_ptr(int);                 // func_ptr与func_ptr2本质是一样的，选择哪种定义方式看你的喜好
19 typedef void (*func_ptr2)(int);                // 参考：http://www.cnblogs.com/qrlozte/p/4439002.html
20 void dosomething_one(func_ptr ptr);
21 void dosomething_two(func_ptr2 ptr);
22 
23 // 方法3,4,5
24 
25 void dosomething_three(void (MyClass::*my_ptr)(int)); 
26 
27 typedef void FuncType(int);
28 typedef FuncType MyClass::*MyClassFuncType;
29 
30 typedef void (MyClass::*MemberFuncType)(int);
31 
32 void dosomething_four(MyClassFuncType ptr);
33 
34 void dosomething_five(MemberFuncType ptr);
35 
36  
37 
38 int main() {
39     /*
40         方法1,2本质是一样的
41         方法3,4,5本质也是一样的
42     */
43     dosomething_one(my);
44     dosomething_two(my);
45     dosomething_three(&MyClass::my);
46     dosomething_four(&MyClass::my);
47     dosomething_five(&MyClass::my);
48     return 0;
49 } ///:~
50 
51 void my(int arg)
52 {
53     cout << arg << endl;
54 }
55 
56 
57 void dosomething_one(func_ptr ptr)
58 {
59     ptr(1);
60 }
61 
62 void dosomething_two(func_ptr ptr)
63 {
64     ptr(2);
65 }
66 
67 void dosomething_three(void (MyClass::*my_ptr)(int))
68 {
69     MyClass *obj = new MyClass;
70     (obj->*my_ptr)(3);
71     delete obj;
72 }
73 
74 void dosomething_four(MyClassFuncType ptr)
75 {
76     MyClass *obj = new MyClass;
77     (obj->*ptr)(4);
78     delete obj;
79 }
80 
81 void dosomething_five(MemberFuncType ptr)
82 {
83     MyClass *obj = new MyClass;
84     (obj->*ptr)(5);
85     delete obj;
86 }