有什么问题啊，大牛们
#include <stdio.h>
#include <stdlib.h>

union u{
unsigned a:2;
unsigned b:4;
char c:5;
char d;
}b={1};
union u func()
{

return b;}
int main(void)
{

union u g;
g=func(g);
printf( "%d ",g.a);
getchar();
return 0;
}

[解决办法]
union u func()
----------------
func()函数没有参数吗？