Clippy lint · Pedantic · checked with Clippy 0.1.99

clippy::copy_iterator: Checks for types that implement Copy as well as Iterator

What it meansChecks for types that implement Copy as well as Iterator. It is in the pedantic group and off by default.

Does it matter?

Implicit copies can be confusing when working with iterator combinators.

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. Change the code by hand:

Flagged

#[derive(Copy, Clone)]
struct Countdown(u8);

impl Iterator for Countdown {
    // ...
}

let a: Vec<_> = my_iterator.take(1).collect();
let b: Vec<_> = my_iterator.collect();

Turn it off, or on

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

Whole crate (Cargo.toml)

[lints.clippy]
copy_iterator = "warn"

In code

#![warn(clippy::copy_iterator)]

One run

cargo clippy -- -W clippy::copy-iterator

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.

Pedanticgroup

allowdefault level

nofixed by cargo clippy --fix

1.30.0added in Rust

Clippy's own documentation

What it does

Checks for types that implement Copy as well as Iterator.

Why is this bad?

Implicit copies can be confusing when working with iterator combinators.

Example

#[derive(Copy, Clone)]
struct Countdown(u8);

impl Iterator for Countdown {
    // ...
}

let a: Vec<_> = my_iterator.take(1).collect();
let b: Vec<_> = my_iterator.collect();

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

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