error[E0308]: mismatched types --> $DIR/wrong-ret-type.rs:2:49 | LL | fn mk_int() -> usize { let i: isize = 3; return i; } | ----- ^ expected `usize`, found `isize` | | | expected `usize` because of return type | help: you can convert an `isize` to a `usize` and panic if the converted value doesn't fit | LL | fn mk_int() -> usize { let i: isize = 3; return i.try_into().unwrap(); } | ++++++++++++++++++++ error: aborting due to previous error For more information about this error, try `rustc --explain E0308`.