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.
Btw. you get a "project1.lpr(7,10) Warning: Case statement does not
handle all possible cases" in the program below anyway:
program Project1;
type
THoleEnum = (two=2, four=4);
var
E: THoleEnum;
begin
case E of
two: ;
four: ;
end;
end.
What will you do now, disable case-of for enumerations with holes
because the compiler cannot handle the holes correctly in the strict FPC
POV way?
Ondrej
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