clippy::manual_unwrap_or: this pattern reimplements `Option::unwrap_or`

What you see

warning: this pattern reimplements `Option::unwrap_or`
 --> main.rs:4:1
  |
4 | / match foo {
5 | |     Some(v) => v,
6 | |     None => 1,
7 | | };
  | |_^ help: replace with: `foo.unwrap_or(1)`
  |
  = help: for further information visit https://rust-lang.github.io/rust-clippy/stable/index.html#manual_unwrap_or
  = note: `#[warn(clippy::manual_unwrap_or)]` on by default

Real output of Clippy 0.1.99 (Rust 1.99) on the example below. Names and line numbers in yours will differ.

Does it matter?

Concise code helps focusing on behavior instead of boilerplate.

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

let foo: Option<i32> = None;
match foo {
    Some(v) => v,
    None => 1,
};

Write this instead

let foo: Option<i32> = None;
foo.unwrap_or(1);

Turn it off, or on

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

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

[lints.clippy]
manual_unwrap_or = "allow"

cargo clippy -- -A clippy::manual-unwrap-or

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.