clippy::needless_match: Checks for unnecessary match or match-like if let returns for Option and Result when function signatures are the same

Does it matter?

This match block does nothing and might not be what the coder intended.

Code that does something simple in a complicated way. Warns by default.

How to fix it

Clippy can fix this one for you: run cargo clippy --fix (add --allow-dirty if you have uncommitted changes). Review the diff before you commit.

Flagged

fn foo() -> Result<(), i32> {
    match result {
        Ok(val) => Ok(val),
        Err(err) => Err(err),
    }
}

fn bar() -> Option<i32> {
    if let Some(val) = option {
        Some(val)
    } else {
        None
    }
}

Write this instead

fn foo() -> Result<(), i32> {
    result
}

fn bar() -> Option<i32> {
    option
}

Turn it off, or on

Allow it where it does not fit your code, as narrowly as you can:

#[allow(clippy::needless_match)]
fn my_function() { /* ... */ }

[lints.clippy]
needless_match = "allow"

cargo clippy -- -A clippy::needless-match

The [lints] table needs Rust 1.74 or newer. In a workspace, put it under [workspace.lints.clippy] and add [lints] workspace = true to each member.