Zonbi

This is an experiment to make it possible to type-erase non-'static types.

How it works

With #[derive(Zonbi)], the type gets an implementation for getting a version of the type where all lifetimes are replaced with the given one. Manual implementation is unsafe because the user must assure that the Casted<'z> type is the same as the one of the implementer.

This is used in ZonbiId, a wrapper around TypeId, which different from it's inside value, has the additional definition of behaviour for non-'static types. ZonbiId is unique for every type, excluding its lifetimes. Under the hood, it just uses the Zonbi trait to get the 'static version of the type and gets its TypeId.

For saving this in a Box, we can use BoxCage<'life>.

I tried to not force the wrapper type, so it's also possible to for example use Rc or Arc, but I couldn't get it running. Help appreciated :D

The cage has an associated lifetime and can hold any type whose lifetimes are equal or longer than its assocaited one. When downcasting the cage back to its type, we get a version of the type back where all the lifetimes are replaced with 'life of the cage, thus being safe.

License

Dual-licensed under Apache-2.0 and MIT