🚀 go-pugleaf

jos@and.nl (Jos Horsmeier) writes:
>In article <1992Nov21.005207.9741@lucid.com> jss@lucid.com (Jerry Schwarz) writes:
>|The standard says  (refering to allocation routines)
>|	If the size of the space requested is zero, the behavior
>|	is implementation-defined; the value returned shall be
>|	either a null pointer or a unique pointer.
>|I have always read "unique pointer" as meaning different from
>|previously allocated pointers including pointers previously
>|returned by malloc(0).  However I have just been talking to
>|some people who insist it means that the same pointer is returned
>|on each call of malloc(0).
>Quite an interesting question ... the answer all depends on the meaning
>of the word `unique'.

Two sentences earlier, the same paragraph says "Each such allocation shall
yield a pointer to an object disjoint from any other object."  malloc() et
al always returns an object; each call results in an object disjoint from
any other object; malloc(0) is therefore entitled to return either NULL
or "an object disjoint from any other object".  Therefore,  malloc(0) may
*not* keep returning pointers to the same dedicated zero-size "object"
(unless, of course, that malloc()ed pointer is freed immediately each time).

Sometimes, you have to read more than one sentence to understand the C
standard.