error[E0005]: refutable pattern in function argument: `(_, _)` not covered --> $DIR/refutable-pattern-errors.rs:1:9 | LL | fn func((1, (Some(1), 2..=3)): (isize, (Option, isize))) { } | ^^^^^^^^^^^^^^^^^^^^^ pattern `(_, _)` not covered | = note: the matched value is of type `(isize, (Option, isize))` error[E0005]: refutable pattern in local binding: `(i32::MIN..=0_i32, _)` and `(2_i32..=i32::MAX, _)` not covered --> $DIR/refutable-pattern-errors.rs:5:9 | LL | let (1, (Some(1), 2..=3)) = (1, (None, 2)); | ^^^^^^^^^^^^^^^^^^^^^ patterns `(i32::MIN..=0_i32, _)` and `(2_i32..=i32::MAX, _)` not covered | = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html = note: the matched value is of type `(i32, (Option, i32))` help: you might want to use `if let` to ignore the variants that aren't matched | LL | if let (1, (Some(1), 2..=3)) = (1, (None, 2)) { todo!() } | ++ ~~~~~~~~~~~ error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0005`.