inefficient_unwrap_or

Default: Enabled

Source Code

What it does

Finds calls of Option::unwrap_or or Result::unwrap_or which can be optimized by lazy-evaluation, using unwrap_or_else.

Example

fn foo() -> usize {
    // Some heavy computation here
    0
}

let x: Option<i32> = None;
let y = x.unwrap_or(foo());

Can be optimized:

let y = x.unwrap_or_else(|| foo());