error[E0562]: `impl Trait` is not allowed in static types --> $DIR/issue-86642.rs:1:11 | LL | static x: impl Fn(&str) -> Result<&str, ()> = move |source| { | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: `impl Trait` is only allowed in arguments and return types of functions and methods error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0562`.