Подскажите, как изменить бит в байте на С++?

#include <bitset>
#include <iostream>
using namespace std;

unsigned char pow(unsigned char z)
{ unsigned char i=z;
for(z=1;i;i--) z*=2;
return z;
}

unsigned char changebit(unsigned char b,unsigned char p)
{
unsigned char t=b/pow(p);
return b+(1-(t-t/2*2)*2)*pow(p);
}

int main()
{
unsigned char b,p;
for(b=0;b-0xFF;b++,cout << endl)
for(p=0;p-8;p++) cout << unsigned(p) << ": " << bitset<8>(b) << " => " << bitset<8>(changebit(b,p)) << endl;
for(p=0;p-8;p++) cout << unsigned(p) << ": " << bitset<8>(b) << " => " << bitset<8>(changebit(b,p)) << endl;
return 0;
}