On Sat, 6 Jul 2019, Ondrej Pokorny wrote:
On 05.07.2019 22:44, J. Gareth Moreton wrote:
In the meantime, I've extended your AS/IS patch over here
<https://bugs.freepascal.org/view.php?id=33603> to create efficient code
for x86 platforms, although currently it only does a range check and won't
correctly handle enumerations with holes. If non-contiguous enumerations
are going to be allowed, we'll need to design an algorithm that can cover
these holes with the smallest number of Boolean conditions.
IMO handling holes in enumerations is just a pure waste of time and energy.
Delphi documents them as valid and the FPC compiler handles them as valid as
well. IMO it is just an unnecessary extra added limitation to disable IS/AS
on them. Furthermore they are used mainly for very specific needs, so are
very marginal. The effort to make this work just doesn't pay off.
After considering what Ondrej pointed out about the behaviour of FPC and
delphi, I agree that checking lower and upper bounds should be sufficient.
Michael.
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