判断结构体中某成员的位置

#define PARAM_OFFSET(Strct, Field) ((unsigned long)&(((Strct *)0)->Field))

struct abc
{
    int a;
    int b;
    int c;
};

void main()
{
    printf("%d/n", PARAM_OFFSET(abc, a));
    printf("%d/n", PARAM_OFFSET(abc, b));
    printf("%d/n", PARAM_OFFSET(abc, c));
}