标签：blog io 2014 amp size log c file
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/*
有符号 结构体1
*/
struct bits
{
int b1:5;
/*
因为是int型，最大设置32位，由于int型是有符号整形,
所以这里5位为有符号类型。
11111 -1
10000 -16
01111 15
00000 0
*/
int :2;
int b2:2;
/*
11 -1
10 -2
01 1
00 0
*/
int b3:1;
/*
1 -1
0 0
*/
};
/*
无符号 结构体2
*/
struct bits
{
unsigned int b1:5;
unsigned int :2;
unsigned int b2:2;
unsigned int b3:1;
};
int
main()
{
struct bits b;
// int a = 0b1111111111111111;
int a = 0b0100110101000101;
memcpy(&b, &a, sizeof(b));
// memcpy(&b, "EM", sizeof(b));
printf("0x%X\n", b);
printf("b.b1 = %d\n", b.b1);
printf("b.b2 = %d\n", b.b2);
printf("b.b3 = %d\n", b.b3);
}
/*
int a = 0b0100110101000101;
0x4D45
b.b1 = 5
b.b2 = -2
b.b3 = 0
int a = 0b1111111111111111;
0xFFFF
b.b1 = -1
b.b2 = -1
b.b3 = -1
int a = 0b0100110101000101;
0x4D45
b.b1 = 5
b.b2 = 2
b.b3 = 0
int a = 0b1111111111111111;
0xFFFF
b.b1 = 31
b.b2 = 3
b.b3 = 1
*/
结构体位制 中存在 有符号 与 无符号 -- C,布布扣,bubuko.com
标签：blog io 2014 amp size log c file
原文地址：http://blog.csdn.net/cy_cai/article/details/38380101
