Xavier

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使用宏操作位 

 1 #include "stdafx.h"
 2 
 3 //取得unsigned int变量的第n位的值是0还是1
 4 #define getvalue(x,n) x<<(32-n)>>(32-1)
 5 
 6 //设置第n位为1
 7 #define  setByteO(x,n) x|1<<(n-1)
 8 
 9 //设置第n位为0
10 #define  setByteZ(x,n) x&(~(1<<(n-1)))
11 
12 //清零
13 #define clear(x) ~(x|~0)
14 
15 int main(int argc, _TCHAR* argv[])
16 {
17     unsigned int a= 21;
18 
19     int c = getvalue(a,4);
20 
21     unsigned int d = setByteO(a,4);
22 
23     int e = getvalue(d,4);
24 
25     unsigned int f = setByteZ(d,4);
26 
27     int g = getvalue(f,4);
28 
29     int h = clear(f);
30 
31     return 0;
32 }

 

posted on 2013-07-23 15:38  .Xavier.zhang  阅读(295)  评论(0)  编辑  收藏  举报