Up to this crate was created, feature impl_trait_in_assoc_type is not stable, so we cannot have a trait with asynchronous function. Although we already have async-trait, it has a shortcoming: each Future stores on heap. That is to say, more asynchronous function you call, more allocation caused. This crate is exists to settle this problem.
But notice, this crate is just for experiment.
This crate provided a box with a compile-time determined memory layout. That is to say, the inner type is actually has a known size, but the type is elimated and can be casted to a unsized type (e.g. DST) at runtime.
Unfortunately, due to feature coerce_unsized is not stable, we cannot coerce the boxed value to any trait object. If needed, you should implement Coerce trait in coerce module manually with unsafe code yourself.
Only Future is implemented by default.