I am not aware of the current status of reflection, but my hope would be that hand-written type-erasure classes will be a thing of the past in C++23/26. I don't have an opinion on whether we need a "unique_any" but it would be a shame if we add it in C++23 and then in C++26 it could have just been a typedef: "using unique_any = type_class<no_member_functions, unique_storing>;"

Am 28.05.2020 um 15:41 schrieb Antony Polukhin via Std-Proposals:

Hi,

Is there a proposal for std::any like type that does not require held types to be copyable and has unique ownership of the held data?

Is there interest in such class?

We have an in house implementation that I find very useful for storing structures that contain unique_ptr (Flatbuffers, recursive types) and even non-movable types with mutexes.