函数指针数组的最佳实践

 1 #include<iostream>
 2 #include<fstream>
 3 #include<string.h>
 4 using namespace std;
 5 
 6 class Student;
 7 
 8 typedef void(CALL)(Student*,int);
 9 
10 class Student
11 {
12 public:
13     string name;
14     int age;
15     char sex;
16 public:
17     Student(){}
18     ~Student(){}
19 };
20 
21 void write_object(Student *students,int size)
22 {
23     ofstream ofs("text.bat");
24     if(ofs)
25     {
26         for(int i=0;i<size;i++)
27         {
28             cin>>students[i].name>>students[i].age>>students[i].sex;
29             ofs.write(reinterpret_cast<const char*>(&students[i]),sizeof(students[i]));
30         }
31     }
32     else
33     {
34         cout<<"write failed"<<endl;
35     }
36     ofs.close();
37 }
38 
39 void read_object(Student *students,int size)
40 {
41     ifstream ifs("text.bat");
42     if(ifs)
43     {
44         for(int i=0;i<size;i++)
45         {
46             ifs.read(reinterpret_cast<char*>(&students[i]),sizeof(students[i]));
47         }
48     }
49     else
50     {
51         cout<<"write failed"<<endl;
52     }
53     ifs.close();
54 }
55 
56 void show_students(Student *students,int size)
57 {
58     for(int i=0;i<size;i++)
59     {
60         cout<<students[i].name<<","<<students[i].age<<","<<students[i].sex<<endl;
61     }
62 }
63 
64 #if 0
65 void clear(Student *students,int size)
66 {
67     for(int i=0;i<size;i++)
68     {
69         memset(reinterpret_cast<void*>(&students[i]),0,sizeof(students[i]));
70     }
71 }
72 #endif 
73 
74 int main()
75 {
76     Student students[3];
77     int size = sizeof(students)/sizeof(students[0]);
78     
79     CALL *arrays[5]={write_object,show_students,read_object,show_students,clear};
80     
81     for(int i=0;i<5;i++)
82     {
83         arrays[i](students,size);    
84     }
85     
86     return 0;
87 }

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