#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(int argc, char** argv)
{
    union
    {
        struct
        {
            char a:1;
            char b:3;
            char c:4;
        }d;
        unsigned char e;
    } f;
    f.e = 0xb9;
    printf("test %d,%d,%d\n",f.d.a,f.d.b,f.d.c);
    return 0;
}

test -1,-4,-5