#![deny(panicking_unwrap, unnecessary_unwrap)] #![allow(if_same_then_else)] fn main() { let x = Some(()); if x.is_some() { x.unwrap(); // unnecessary } else { x.unwrap(); // will panic } if x.is_none() { x.unwrap(); // will panic } else { x.unwrap(); // unnecessary } let mut x: Result<(), ()> = Ok(()); if x.is_ok() { x.unwrap(); // unnecessary x.unwrap_err(); // will panic } else { x.unwrap(); // will panic x.unwrap_err(); // unnecessary } if x.is_err() { x.unwrap(); // will panic x.unwrap_err(); // unnecessary } else { x.unwrap(); // unnecessary x.unwrap_err(); // will panic } if x.is_ok() { x = Err(()); x.unwrap(); // not unnecessary because of mutation of x // it will always panic but the lint is not smart enoguh to see this (it only checks if conditions). } else { x = Ok(()); x.unwrap_err(); // not unnecessary because of mutation of x // it will always panic but the lint is not smart enoguh to see this (it only checks if conditions). } } fn test_complex_conditions() { let x: Result<(), ()> = Ok(()); let y: Result<(), ()> = Ok(()); if x.is_ok() && y.is_err() { x.unwrap(); // unnecessary x.unwrap_err(); // will panic y.unwrap(); // will panic y.unwrap_err(); // unnecessary } else { // not statically determinable whether any of the following will always succeed or always fail: x.unwrap(); x.unwrap_err(); y.unwrap(); y.unwrap_err(); } if x.is_ok() || y.is_ok() { // not statically determinable whether any of the following will always succeed or always fail: x.unwrap(); y.unwrap(); } else { x.unwrap(); // will panic x.unwrap_err(); // unnecessary y.unwrap(); // will panic y.unwrap_err(); // unnecessary } let z: Result<(), ()> = Ok(()); if x.is_ok() && !(y.is_ok() || z.is_err()) { x.unwrap(); // unnecessary x.unwrap_err(); // will panic y.unwrap(); // will panic y.unwrap_err(); // unnecessary z.unwrap(); // unnecessary z.unwrap_err(); // will panic } if x.is_ok() || !(y.is_ok() && z.is_err()) { // not statically determinable whether any of the following will always succeed or always fail: x.unwrap(); y.unwrap(); z.unwrap(); } else { x.unwrap(); // will panic x.unwrap_err(); // unnecessary y.unwrap(); // unnecessary y.unwrap_err(); // will panic z.unwrap(); // will panic z.unwrap_err(); // unnecessary } } fn test_nested() { fn nested() { let x = Some(()); if x.is_some() { x.unwrap(); // unnecessary } else { x.unwrap(); // will panic } } }