Bit Switching - How?

[Leo de Wit]

In article <18944 at adm.BRL.MIL> rbj at dsys.icst.nbs.gov (Root Boy Jim) writes:
    []
|void bit flip(x,y,mask) int *x, *y;	/* mask can be more than one bit */
|{
|	int z = (x ^ y) & mask;		/* difference of interesting bits */
|	if (z)				/* some bits differ */
|		x ^= z, y^= z;		/* flip those that do */
|}

What is this piece of code supposed to do? Since its return type is
'void', one would expect it to dereference its pointer arguments; it
doesn't (so in fact it is a pure function, and since it returns
nothing, a no-op 8-).

Well, probably the x, y in the function body should read *x, *y; and
what about renaming 'void bit flip' to 'void bitflip' ? Makes my
compiler happier. B.T.W. am I the first one to spot this?

    Leo.