error[E0308]: mismatched types --> $DIR/unboxed-closures-type-mismatch.rs:5:15 | LL | let z = f(1_usize, 2); | - ^^^^^^^ expected `isize`, found `usize` | | | arguments to this function are incorrect | note: closure defined here --> $DIR/unboxed-closures-type-mismatch.rs:4:17 | LL | let mut f = |x: isize, y: isize| -> isize { x + y }; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: change the type of the numeric literal from `usize` to `isize` | LL | let z = f(1_isize, 2); | ~~~~~ error: aborting due to previous error For more information about this error, try `rustc --explain E0308`.