[Lazarus] Pointer type handling

[Anton Kavalenka]

On 09.12.2013 18:06, Leonardo M. Ramé wrote:
> Hi, I'm passing a pointer buffer as void * to a C library that returns
> Uint8 or Uint16 (and signed types).
>
> If I explicitly declare the buffer as PByte, PWord, etc. I get exactly
> what I need, but, I would like to work with an abstract type (for
> example Pointer) and cast it depending on a flag returned by the
> library.
>
> If I pass a Pointer (instead of a PWord or PByte) and cast it to PWord,
> for example. I get the same result if I have passed a PByte.
>
> How can I handle a situation like this without explicitly define each
> type?.
>
> Regards,
PPointerCast=^TPointerCast
TpointerCast=record
case integer of
0:(pb:PByte);
1:(pw:PWord);
2:(pd:PDword);
3:(pu:PtrUint);
4:(pi:PtrInt);
end;

function some_function(ptr:TPointerCast):boolean;

regards,
Anton