C语言学习 函数指针与typeof

 1 #include <stdio.h>
 2 #include <stdlib.h>
 3 #include <io_utils.h>
 4 
 5 // 1
 6 int *(f1(int, double));
 7 
 8 // 2
 9 int (*f2)(int, double);
10 
11 // 3
12 int *(*f3)(int, double);
13 
14 // 4
15 // int (*f4)(int, double)[];
16 
17 // 5
18 // int (*f5)[](int, double);
19 
20 typedef int (*Func)(int, double);
21 
22 typedef int Boolean;
23 typedef int *IntPtr;
24 typedef int IntArray[];
25 
26 int Add(int left, double right) {
27   return (int) (left + right);
28 }
29 
30 void InitPointer(int **ptr, int length, int default_value) {
31   *ptr = malloc(sizeof(int) * length);
32   for (int i = 0; i < length; ++i) {
33     (*ptr)[i] = default_value;
34   }
35 }
36 
37 int main() {
38   int a;
39   IntPtr p;
40   IntArray players = {1,3,4,5};
41   PRINT_HEX(&main);
42   PRINT_HEX(&InitPointer);
43 
44   void (*func)(int **ptr, int length, int default_value) = &InitPointer;
45 
46   func(&p, 10, 0);
47   InitPointer(&p, 10, 0);
48 
49   (*func)(&p, 10, 0);
50   (*InitPointer)(&p, 10, 0);
51 
52 
53   PRINT_INT_ARRAY(p, 10);
54 
55   free(p);
56 
57   Func func1 = &Add;
58   int result = func1(1, 3.0);
59   PRINT_INT(result);
60   return 0;
61 }