时间标志

typedef union {
  struct {
    uint16_t cnt : 15;
    uint16_t flag : 1;
  };
  uint16_t itself;
} time_flag_u;

#include <stdio.h>

typedef unsigned int uint16_t;

typedef union {
  struct {
    uint16_t cnt : 15;
    uint16_t flag : 1;
  };
  uint16_t itself;
} time_flag_u;

time_flag_u time;

int main()
{
    time.cnt = 32767;
    time.flag = 1;
    printf("time.cnt = %d\n", time.cnt);
    printf("time.flag = %d\n", time.flag);
    printf("\n");
    time.itself = 0;
    printf("time.cnt = %d\n", time.cnt);
    printf("time.flag = %d\n", time.flag);
   
    return 0;
}

运行结果：
time.cnt = 32767
time.flag = 1

time.cnt = 0
time.flag = 0

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