[fpc-devel] Dangerous optimization in CASE..OF

[Sven Barth]

Ondrej Pokorny <lazarus at kluug.net> schrieb am Fr., 13. Apr. 2018, 12:52:

> On 02.07.2017 18:55, Ondrej Pokorny wrote:
>
> On 02.07.2017 18:49, Jonas Maebe wrote:
>
> No, there is no built-in checked conversion from integer to arbitrary
> enumeration types. That's why I suggested in the bug report that started
> this thread to file a feature request for such a conversion.
>
>
> Very good :)
>
> Are there any disadvantages of the enum-AS operator that prevents its
> introduction?
>
>
> Someone else could already have code that overloads the AS-operator in
> this way, and such a change would break this (you cannot overload operators
> with a built-in meaning). I would be in favour of a new intrinsic.
>
>
> If I am not mistaken, the AS operator cannot be overloaded - so no chance
> to break legacy code here.
>
>
> Because
>
> 1.) you agreed that a built-in checked conversion from integer to
> arbitrary enumeration type is wanted and
> 2.) the AS-operator cannot be overloaded and thus the only argument
> against enum support for AS is not valid
>
> I introduced the AS operator for enumerators in
> https://bugs.freepascal.org/view.php?id=33603
>

What about enums with holes?
Also for constants there could be a compile time check.

Regards,
Sven

>
>
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