For what it's worth, I think that a free function would be better than a
method. In this way it would mimic the syntax and behavior of the
preexisting `any_cast`. Could be called `any_upcast` or something similar.
Or it could take the form of a second template argument of `any_cast` which
controls whether the match has to be exact, or derived classes are allowed.

On Mon, Apr 15, 2024 at 1:45 PM Frederick Virchanza Gotham via
Std-Proposals <std-proposals_at_[hidden]> wrote:

> In the previous two threads entitled:
>
> "Extend std::type_info with more information"
> "Use the exception system to check for bases at runtime"
>
> People were not much interested in extending "std::type_info", but
> rather were particularly interested in adding a new member function to
> "std::any".
>
> Here's the beginnings of a paper for std::any::base:
>
> http://www.virjacode.com/papers/any_base.htm
>
> The implementations are provided in the paper purely just to show that
> it's possible without an ABI break. Compiler vendors will implement
> it much more efficiently.
> --
> Std-Proposals mailing list
> Std-Proposals_at_[hidden]
> https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals
>

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