RS.CLIPPY.SINGLE_OPTION_MAP

Checks for functions with method calls to `.map(_)` on an arg of type `Option` as the outermost expression.

This checker is a Clippy lint created by The Rust Project Contributors. The documentation shown here is a copy of the original documentation for: single_option_map. Copyright ©2025 The Rust Team. All rights reserved.

What it does

Checks for functions with method calls to .map(_) on an arg of type Option as the outermost expression.

Why is this bad?

Taking and returning an Option<T> may require additional Some(_) and unwrap if all you have is a T.

Example

fn double(param: Option<u32>) -> Option<u32> {
    param.map(|x| x * 2)
}

Use instead:

fn double(param: u32) -> u32 {
    param * 2
}