[fpc-devel] SizeOf( const typcasted as shortstring)

[Sven Barth]

Dmitry Boyarintsev <skalogryz.lists at gmail.com> schrieb am Mo., 13. Aug.
2018, 00:12:

> On Sun, Aug 12, 2018 at 5:40 PM Bart <bartjunk64 at gmail.com> wrote:
>
>> const
>>   x = ShortString('abc');
>> begin
>>   writeln(SizeOf(x));
>> end.
>>
>> Delphi (7) prints 256, fpc prints 3.
>>
>> Is that a bug or an implementation detail?
>>
>
> Implementation detail.
> And it seems to be wrong on Delphi size, because for reason it assigns a
> type to a (non-typed) constant.
> It would make sense to return 256, if the constant was declared like this:
> const
>    x : ShortString = 'abc';
> and fpc does recognize such typed constant as 256 in size.
>
> It's odd that such expression compiles w/o any warnings or notes. (i.e.
> "ignoring typecasting for constant value expressions")
>

Support for typecasts in untyped constants is by design and sometimes
required, e.g. for unsigned 64-Bit values.

Regards,
Sven

>
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