结构体与联合体的一个特殊用法！

#include "iostream"
#include "string.h"
using namespace std;
#include<stdio.h>
typedef struct
{
  unsigned char bit0 : 1;
  unsigned char bit1 : 1;
  unsigned char bit2 : 1;
  unsigned char bit3 : 1;
  unsigned char bit4 : 1;
  unsigned char bit5 : 1;
  unsigned char bit6 : 1;
  unsigned char bit7 : 1;

  unsigned char bit8 : 1;
  unsigned char bit9 : 1;
  unsigned char bit10 : 1;
  unsigned char bit11 : 1;
  unsigned char bit12 : 1;
  unsigned char bit13 : 1;
  unsigned char bit14 : 1;
  unsigned char bit15 : 1;
}bitValue;

typedef union
{
  unsigned int bytedata;
  bitValue  bitdata;
}regValue;

int main()
{
  regValue data;
  data.bytedata = 0xF0F0;

  printf("%d\t", data.bitdata.bit0);
  printf("%d\t", data.bitdata.bit1);
  printf("%d\t", data.bitdata.bit2);
  printf("%d\t", data.bitdata.bit3);
  printf("%d\t", data.bitdata.bit4);
  printf("%d\t", data.bitdata.bit5);
  printf("%d\t", data.bitdata.bit6);
  printf("%d\t", data.bitdata.bit7);

  printf("%d\t", data.bitdata.bit8);
  printf("%d\t", data.bitdata.bit9);
  printf("%d\t", data.bitdata.bit10);
  printf("%d\t", data.bitdata.bit11);
  printf("%d\t", data.bitdata.bit12);
  printf("%d\t", data.bitdata.bit13);
  printf("%d\t", data.bitdata.bit14);
  printf("%d\t", data.bitdata.bit15);
  return 0;
}

用法取自某位博主的博文。