clippy::ref_option_ref: since `&` implements the `Copy` trait, `&Option<&T>` can be simplified to `Option<&T>`

What you see

warning: since `&` implements the `Copy` trait, `&Option<&T>` can be simplified to `Option<&T>`
 --> main.rs:3:8
  |
3 | let x: &Option<&u32> = &Some(&0u32);
  |        ^^^^^^^^^^^^^ help: try: `Option<&u32>`
  |
  = help: for further information visit https://rust-lang.github.io/rust-clippy/stable/index.html#ref_option_ref
  = note: `-W clippy::ref-option-ref` implied by `-W clippy::pedantic`

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?

Since & is Copy, it’s useless to have a reference on Option<&T>.

Stricter lints with some false positives. Off by default; opt in with clippy::pedantic.

How to fix it

Clippy does not fix this one automatically (its suggestion may change behaviour, so it only shows it). Change the code by hand:

Flagged

let x: &Option<&u32> = &Some(&0u32);

Write this instead

let x: Option<&u32> = Some(&0u32);

Turn it off, or on

It is off by default. To use it, set it to warn or deny:

[lints.clippy]
ref_option_ref = "warn"

#![warn(clippy::ref_option_ref)]

cargo clippy -- -W clippy::ref-option-ref

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.