论坛首页 › ARM技术论坛 › 快速获取结构体成员大小

呐咯密密 发表于 2023-5-29 13:50

快速获取结构体成员大小

#include <stdio.h>   

// 获取结构体成员大小
#defineGET_MEMBER_SIZE(type, member)   sizeof(((type*)0)->member)

// 获取结构体成员偏移量
#defineGET_MEMBER_OFFSET(type, member)((size_t)(&(((type*)0)->member)))

typedef struct _test_struct0
{
char x;
char y;
char z;
}test_struct0;

typedef struct _test_struct1
{
char a;
char c;
short b;         
int d;
test_struct0 e;
}test_struct1;

int main(int arc, char *argv[])
{
printf("GET_MEMBER_SIZE(test_struct1, a) = %ld\n", GET_MEMBER_SIZE(test_struct1, a));
    printf("GET_MEMBER_SIZE(test_struct1, c) = %ld\n", GET_MEMBER_SIZE(test_struct1, c));
printf("GET_MEMBER_SIZE(test_struct1, b) = %ld\n", GET_MEMBER_SIZE(test_struct1, b));
printf("GET_MEMBER_SIZE(test_struct1, d) = %ld\n", GET_MEMBER_SIZE(test_struct1, d));
    printf("GET_MEMBER_SIZE(test_struct1, e) = %ld\n", GET_MEMBER_SIZE(test_struct1, e));
    printf("test_struct1 size = %ld\n", sizeof(test_struct1));

printf("GET_MEMBER_OFFSET(a): %ld\n", GET_MEMBER_OFFSET(test_struct1, a));
printf("GET_MEMBER_OFFSET(c): %ld\n", GET_MEMBER_OFFSET(test_struct1, c));
printf("GET_MEMBER_OFFSET(b): %ld\n", GET_MEMBER_OFFSET(test_struct1, b));
printf("GET_MEMBER_OFFSET(d): %ld\n", GET_MEMBER_OFFSET(test_struct1, d));
printf("GET_MEMBER_OFFSET(e): %ld\n", GET_MEMBER_OFFSET(test_struct1, e));

return 0;
}

yangjiaxu 发表于 2023-5-31 08:52

真不错，这种就可以用已有的库实现获取数组的大小，非常节省时间呢

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