Relying on just `as_any` was error prone and will become redundant in
the future, once upcasting will be stable, we also won't to impose a
restriction on to which concrete type we're casting, since casting
to a type that doesn't implement a base trait doesn't make much
sense.
Co-authored-by: Kirill Chibisov <contact@kchibisov.com>
This removes the direct requirement to implement `as_any` and it could
be just derived.
Also implement HasDisplayHandle for dyn ActiveEventLoop + '_.
Suggested-by: daxpedda <daxpedda@gmail.com>
Removes the once_cell dependency, instead using std::sync::OnceLock and a
minimal polyfill for std::sync::LazyLock, which may be stabilized soon
(see rust-lang/rust#121377).
This should not require a bump in MSRV, as OnceLock was stabilized in 1.70,
which this crate is using.
