[Gllug] Pointer arithmetic with void *

[Jonathan Harker]

On Wednesday 14 Aug 2002 4:35 pm, you wrote:
> >If you want to do this sort of thing, you should cast via char*:
>
> Yes, that's what I've been doing up until now. I just wondered if it
> was strictly necessary.

Don't know much about C standard, but C++98 says you can't do pointer 
arithmetic with void*. I imagine C99 would say the same. Best to avoid and 
like Alain says, cast to (char*)

<ramble>
Just out of interest, I take it this is pretty low level stuff you're doing? 
Playing with and casting void* can be dangerous! Is there a way you could 
cast the void* that mmap returns directly to a struct?

eg.

some_struct* p;
p = mmap(....);

suppose not if you can't tell beforehand... </ramble>

:-)

Luv Jon

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