[Development] QtCS 2017 QtCore sessions

[Konstantin Tokarev]

01.11.2017, 18:46, "Thiago Macieira" <thiago.macieira at intel.com>:
> On quarta-feira, 1 de novembro de 2017 08:25:01 PDT Konstantin Tokarev wrote:
>>  > No, not really, since it's already limited to half the full VM space. No
>>  > object can be larger than that. Using unsigned is unnecessary.
>>
>>  Using unsigned for size types is crucial in preventing signed overflow in
>>  pathological cases.
>
> Using signed for size types is crucial because the API expects to be able to
> count backwards from the end and needs to report failure in other situations.
> So unsigned is simply ruled out.

Indeed, it's crucial to keep backward compatibility in API

(Yet counting backwards is nothing more than a sugar, and STL containers
cope fine with size_t)

>
> There are also no pathological cases since there is no overflow.

There is overflow, try e.g. QByteArray::fromBase64() with array of size larger than
INT_MAX / 3

If size was unsigned such bugs wouldn't lead to crashes or potential security issues

>
> --
> Thiago Macieira - thiago.macieira (AT) intel.com
>   Software Architect - Intel Open Source Technology Center
>
> _______________________________________________
> Development mailing list
> Development at qt-project.org
> http://lists.qt-project.org/mailman/listinfo/development

-- 
Regards,
Konstantin