error[E0282]: type annotations needed for `Result<(), E>` --> $DIR/cannot-infer-closure-circular.rs:7:14 | LL | let x = |r| { | ^ LL | let v = r?; LL | Ok(v) | ----- type must be known at this point | help: consider giving this closure parameter an explicit type, where the type for type parameter `E` is specified | LL | let x = |r: Result<(), E>| { | +++++++++++++++ error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0282`.