[fpc-pascal] more questions on storage
Marco van de Voort
marcov at stack.nl
Fri Sep 28 23:16:43 CEST 2007
> On Thu, 27 Sep 2007 12:38:13 +0200 (CEST)
> > > Pointer(AnsiString) <> Pointer(PChar(AnsiString))
> > >
> > > To get a no-op typecase you can use:
> > > MyPChar:=PChar(Pointer(AnsiString));
> > Is this delphi compat, and if yes, what is this exactly for?
> I don't know.
> The change broke some lazarus code and now it is polluted by the ugly
> double type casts, just to get some no-op type casts.
> Because this fact is not widely known or often forgotten, many use the
> PChar() as simple type cast. That's why the lcl interfaces already got
> into troubles several times, so everytime we get strange errors I first
> search for these typecasts.
> Maybe we should mention this fact at a more prominent place in the
> wiki and docs.
Maybe yes. I quickly checked dateutils and strutils and found a few cases
that were easy to "fix". (all using a NIL checking routine immediately
Sysutils however had 39, and I suspect several would crash when changed,
since few routines have empty string early-outs like e.g. strutils has.
I'm still investigating those.
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