Please give example of such type

вт, 28 окт. 2025 г. в 19:45, Sebastian Wittmeier via Std-Proposals <
std-proposals_at_[hidden]>:

> Yes, but normally the constructors/destructors/move/copy are called, when
> the memory location changes. So the type has full control. It you backup
> during the lifetime without using the class member functions for a
> non-trivially movable type, this can run into problems.
>
>
> -----Ursprüngliche Nachricht-----
> *Von:* Thiago Macieira via Std-Proposals <std-proposals_at_[hidden]>
> *Gesendet:* Di 28.10.2025 15:00
> *Betreff:* Re: [std-proposals] Way to get rid of valueless_by_exception
> in std::variant
> *Anlage:* signature.asc
> *An:* std-proposals_at_[hidden];
> *CC:* Thiago Macieira <thiago_at_[hidden]>;
> On Tuesday, 28 October 2025 05:59:12 Pacific Daylight Time Sebastian
> Wittmeier
> via Std-Proposals wrote:
> > No, the memory can be used to communicate with the hardware or special
> flags
> > (e.g. non-pageable) were assigned with the help of the operating system.
>
> I don't think that's a valid use of std::variant. What you're saying is
> true
> for some user-provided type, but I don't see how it could apply to
> std::variant, for two reasons:
>
> 1) the user should not know the layout of std::variant, and thus how
> reading
> it or writing to it actually performs HW operations
>
> 2) by definition, a std::variant could contain other types instead, which
> make
> even less sense in special memory.
>
> --
> Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org
> Principal Engineer - Intel Data Center Group
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