Type inference regression in rustc 1.18 #42545
Description
https://github.com/khuey/rustc-1.18-regression
I'm not sure that this is a minimal testcase, but it's small enough to poke around at. With rustc 1.17 this compiles fine. With 1.18 I get
error[E0284]: type annotations required: cannot resolve `<_ as futures::IntoFuture>::Future == _` --> src/lib.rs:15:18 | 15 | Box::new(join_all(vec2.iter() | __________________^ 16 | | .map(move |_| { 17 | | iter::<_, _, ()>(vec1.iter() 18 | | .filter_map(move |_| { ... | 24 | | }) 25 | | })))