*p++ = *p results?

[Doug Gwyn]

In article <312 at imagen.UUCP> kevin at imagen.UUCP (Kevin L. Malloy) writes:
>In the statement *p++ = *p; what will be the result?  Will p be equal
>to itself or will p be equal to the next value it is pointing to?
>In other words should p be incremented after it is evaluated or should
>p be incremented after the assignment operation is finished?-- 

Obviously `p' equals itself!  I will assume you mean "does `p'
point to the next value after the one `p' initially pointed to?"

The technically correct answer is, `p' must be incremented
by the time the next "sequence point" (defined by X3J11) is
reached.  My copy of the draft standard is not at hand at the
moment, but I believe there is no sequence point until after
the assignment.  That would mean that either result is legal;
in other words, don't write code like this.