Clippy lint · Style · checked with Clippy 0.1.99

clippy::match_result_ok: Checks for unnecessary ok() in while let

What it meansChecks for unnecessary ok() in while let. It is in the style group and warns by default.

Does it matter?

Calling ok() in while let is unnecessary, instead match on Ok(pat)

Code that works but is not idiomatic Rust. 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

while let Some(value) = iter.next().ok() {
    vec.push(value)
}

if let Some(value) = iter.next().ok() {
    vec.push(value)
}

Write this instead

while let Ok(value) = iter.next() {
    vec.push(value)
}

if let Ok(value) = iter.next() {
       vec.push(value)
}

Turn it off, or on

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

On one item

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

Whole crate (Cargo.toml)

[lints.clippy]
match_result_ok = "allow"

One run

cargo clippy -- -A clippy::match-result-ok

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.

Stylegroup

warndefault level

yesfixed by cargo clippy --fix

1.57.0added in Rust

Clippy's own documentation

What it does

Checks for unnecessary ok() in while let.

Why is this bad?

Calling ok() in while let is unnecessary, instead match on Ok(pat)

Example

while let Some(value) = iter.next().ok() {
    vec.push(value)
}

if let Some(value) = iter.next().ok() {
    vec.push(value)
}

Use instead:

while let Ok(value) = iter.next() {
    vec.push(value)
}

if let Ok(value) = iter.next() {
       vec.push(value)
}

Past names

if_let_some_result

From the Clippy lint list (0.1.99), part of the Rust project, MIT or Apache-2.0. Official entry.

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