Hi,

If I have a declaration as follows... what type is InData and OutData? Pointers? If it is a generic Pointer type, then why doesn't developers simply declare it as pointer? What is the advantage of not mentioning the type then?

procedure TDCP_blowfish.EncryptECB(const InData; var OutData);
begin
...
end

Regards,
- Graeme -

Graeme Geldenhuys wrote

If I have a declaration as follows... what type is InData and OutData? Pointers? If it is a generic Pointer type, then why doesn't developers simply declare it as pointer? What is the advantage of not mentioning the type then?

if you declare parameter as Pointer, then you might be able to pass "nil" So the function should keep that possibility in mind.

Declaring parameter as untype shows that parameter is mandatory.

thanks,
dmitry

dmitry boyarintsev wrote

if you declare parameter as Pointer, then you might be able to pass "nil" So the function should keep that possibility in mind. Declaring parameter as untype shows that parameter is mandatory.

Thanks for the quick response. I looked in the Language Reference documentation for FPC and couldn't find any mention of that. It simply states that untyped parameters are not compatible with any other types and must be cast before used.

I'll point this out to Michael van Canneyt.

Regards,
- Graeme -