bit manipulation - C - Swap a bit between two numbers

Question

I just tried with this code:

void swapBit(unsigned char* numbA, unsigned char* numbB, short bitPosition)//bitPosition 0-x
{
    unsigned char oneShift = 1 << bitPosition;

    unsigned char bitA = *numbA & oneShift;
    unsigned char bitB = *numbB & oneShift;

    if (bitA)
        *numbB |= bitA;
    else
        *numbB &= (~bitA ^ oneShift);

    if (bitB)
        *numbA |= bitB;
    else
        *numbA &= (~bitB ^ oneShift);
}

to swap bit position x of a and b but because of the if() I think there's something better.

Also when i see this:

*numbB &= (~bitA ^ oneShift);

I really think that there's an easier way to do it. If you have something for me, i would take it :)

Thanks in advance

Answer 1

First you should set the corresponding position in a number to 0, and then OR it with the actual bit, removing all of the conditions:

*numbB &= ~oneShift; // Set the bit to `0`
*numbB |= bitA;      // Set to the actual bit value

The same for the other number.