constructor the shared structure in-place
5825 ワード
new(mCblk) audio_track_cblk_t(); placement new
1 #include <iostream>
2 #include <stdio.h>
3 #include <malloc.h>
4
5 class Student
6 {
7 private:
8 int age;
9 int grade;
10 public:
11 Student(void)
12 {
13 age = 5;
14 grade = 10;
15 }
16
17 ～Student(void)
18 {
19 printf("xx
");
20 }
21 };
22
23 int main(void)
24 {
25 Student *pStudent = (Student*)malloc(sizeof(Student));
26 char *p = (char*)pStudent;
27
28 int i = 0;
29 for(i = 0; i < sizeof(Student); i++)
30 *p++ = 0;
31
32 p = (char*)pStudent;
33
34 new(pStudent) Student();
35
36 for(i = 0; i < sizeof(Student); i++)
37 {
38 printf("%u
", (unsigned int)(*p) & off);
39 p++;
40 }
41 delete pStudent;
42 return 0;
43 }
44
45 x86 ：
46 5
47 0
48 0
49 0
50 10
51 0
52 0
53 0