Linux-c对一个十六进制数的某一位取反

enum SWITCH_FLAG {
  SWITCH_ALL_FLAG       = 0,
  SWITCH_WEB_FLAG       = 1,
  ……
}

unsigned int switch_by_bit_value = 0x7FFFFFFF;

void switch_set_bit(int*a,int position,int flg)
{
    int b=1<<position;
    if(flg==0){
        *a&=~b;
    }
    else{
        *a|=b;
    }
}

switch_set_bit(&switch_by_bit_value,SWITCH_WEB_FLAG,1);
switch_set_bit(&switch_by_bit_value,SWITCH_WEB_FLAG,0);