Summary
Prepare TAIT (type alias impl trait) and return type notation (RTN) for stabilization together, giving Rust a coherent story for naming and bounding previously unnameable and unboundable types. TAIT lets users name opaque types like closures, async blocks, and complex iterators without boxing. RTN enables bounds like T::method(..): Send, solving the "Send bound" problem and unblocking widespread use of async fn in traits. This goal also extends RTN to async closures via a new RFC. Full stabilization is blocked on the next-gen trait solver work and is intended to happen late this year.
Needs contributor: The majority of the impl work for TAIT and RTN has been done however the syntactic design for RTN and async closures is incomplete. We're seeking someone willing to help work on the RFC and explore the design space as well as to finalize impl details.
Tasks and status
Summary
Prepare TAIT (type alias impl trait) and return type notation (RTN) for stabilization together, giving Rust a coherent story for naming and bounding previously unnameable and unboundable types. TAIT lets users name opaque types like closures, async blocks, and complex iterators without boxing. RTN enables bounds like
T::method(..): Send, solving the "Send bound" problem and unblocking widespread use of async fn in traits. This goal also extends RTN to async closures via a new RFC. Full stabilization is blocked on the next-gen trait solver work and is intended to happen late this year.Needs contributor: The majority of the impl work for TAIT and RTN has been done however the syntactic design for RTN and async closures is incomplete. We're seeking someone willing to help work on the RFC and explore the design space as well as to finalize impl details.
Tasks and status