Quoth adr <[email protected]>:
> Hi,
> one of the first thing I noticed compiling in plan9 is that arithmetic
> on void* is illegal. Other compilers treat void* as uchar*.
> Conceptually, it makes sense. A pointer to void doesn't point to
> any object. But then I've seen the use of void* in functions (like
> memccpy) when the pointed object is going to be processed as a
> byte array. Local uchar*'s are used to do the trick inside the
> function.
>
arithmetic on void* is a gnu extension. It also implies
sizeof(void) == 1; this is indeed true with gcc.
I also don't think it's useful enough to add a special
case to an already special case: it's rare to be able
to do pointer arithmetic on void and *not* access the
memory, in my experience.
> It wouldn't make more sense to avoid the use of void*
> and just use instead uchar* or better still u8int*?
the unique thing about void* is that there is an implicit
conversion from any pointer type to void*; there is not
for uchar* or u8int*.
memset((u8int*)&x, 0, sizeof(x));
seems unnecessarily clunky.
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