On Tue, Jul 2, 2019 at 7:38 PM Ondrej Pokorny <laza...@kluug.net> wrote:
> A good real-word example is the cast from a pointer:
>
> program Project1;
> uses Classes;
> var
> Value: TPersistent;
> P: Pointer;
> begin
> P := TObject.Create;
> Value := TPersistent(P);
> if Value is TPersistent then
> Writeln('Value is TPersistent')
> else
> Writeln('Value is not TPersistent');
> Readln;
> end.
>
In general, assuming P was a pointer initialized elsewhere (meaning you
really didn't know what it was), why wouldn't you just write this:
if TObject(P) is TPersistent then
Writeln('Value is TPersistent')
else
Writeln('Value is not TPersistent');
Readln;
Behaves as you'd expect, and doesn't require an additional variable.
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