To explain more besides Steve's commit, there has been another RFC that significantly expands the scope of impl Trait. It was accepted, but it also had the effe

To explain more besides Steve's commit, there has been another RFC that significantly expands the scope of impl Trait. It was accepted, but it also had the effect of punting the stabilisation of the feature a bit until things settle down. I don't know if the "conservative" version of impl Trait is going to land first anyway, but I find it just reassuring that people aren't rushing things. (For reference: The original impl Trait: https://github.com/rust-lang/rfcs/pull/1522 https://github.com/rust-lang/rfcs/pull/1522 The refinement, readying it for stabilisation: https://github.com/rust-lang/rfcs/pull/1951 https://github.com/rust-lang/rfcs/pull/1951 The latest one, which gives it more expressive power: https://github.com/rust-lang/rfcs/pull/2071 https://github.com/rust-lang/rfcs/pull/2071 )