It not possible with rust current abstractions you would need: - higher kind types / type constructors - some features to handle differences in the auto-trait

It not possible with rust current abstractions you would need: - higher kind types / type constructors - some features to handle differences in the auto-traits depending on the result of the type constructor - some magic to resolves that --- - OR namespace overloading e.g. read_to_string$sync and read_to_string$async and magic to resolve that But async has A LOT of implications which change subtle things around handling it, like e.g. the handling of lifetimes/borrows, Send, Sync, etc. So this probably wouldn't be worth the complexity it introduces.