This is another case of interface declaration. If you have virtuals, you
first declare pure interface. And you have several implementations of the
interface. It works well in c++.

I talk about the case when I plan to implement some class later, just one
class, without hierarchy. I want to declare his interface, write and
compile tests even before the class is fully defined. Today I have either
to use PIMPL or declare unnecessery interface that is never reused.

I just propose a simpler alternative of interface declaration. The virtual
methods are not there, we do not need it for this case.

On Thu, Aug 26, 2021, 07:41 Thiago Macieira via Std-Proposals <
std-proposals_at_[hidden]> wrote:

> On Wednesday, 25 August 2021 21:30:59 PDT Valery Osheter via Std-Proposals
> wrote:
> > I think that the programmer should have the way to hide the
> implementation
> > details, otherwise the main concept of OOP is not provided by the
> language.
>
> Half of OOP requires use of virtuals. If you're going to argue the need
> for
> partial declarations and hiding implementation details, please include the
> ability to use virtual members and bases.
>
> --
> Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org
> Software Architect - Intel DPG Cloud Engineering
>
>
>
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