Clippy lints / Style
Clippy lint · Style · checked with Clippy 0.1.99
clippy::iter_cloned_collect: called `.iter().cloned().collect()` on a slice to create a `Vec`
What it meansChecks for the use of .cloned().collect() on slice to create a Vec. It is in the style group and warns by default.
What you see
warning: called `.iter().cloned().collect()` on a slice to create a `Vec` --> main.rs:4:27 | 4 | let s2: Vec<isize> = s[..].iter().cloned().collect(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^ | = help: for further information visit https://rust-lang.github.io/rust-clippy/stable/index.html#iter_cloned_collect = note: `#[warn(clippy::iter_cloned_collect)]` on by default help: calling `.to_vec()` is both faster and more readable | 4 - let s2: Vec<isize> = s[..].iter().cloned().collect(); 4 + let s2: Vec<isize> = s[..].to_vec(); |
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?
.to_vec() is clearer
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
let s = [1, 2, 3, 4, 5];
let s2: Vec<isize> = s[..].iter().cloned().collect();
Write this instead
let s = [1, 2, 3, 4, 5];
let s2: Vec<isize> = s.to_vec();
Turn it off, or on
Allow it where it does not fit your code, as narrowly as you can:
On one item
#[allow(clippy::iter_cloned_collect)]
fn my_function() { /* ... */ }Whole crate (Cargo.toml)
[lints.clippy]
iter_cloned_collect = "allow"One run
cargo clippy -- -A clippy::iter-cloned-collectThe [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.
Clippy's own documentation
What it does
Checks for the use of .cloned().collect() on slice to
create a Vec.
Why is this bad?
.to_vec() is clearer
Example
let s = [1, 2, 3, 4, 5];
let s2: Vec<isize> = s[..].iter().cloned().collect();
The better use would be:
let s = [1, 2, 3, 4, 5];
let s2: Vec<isize> = s.to_vec();
From the Clippy lint list (0.1.99), part of the Rust project, MIT or Apache-2.0. Official entry.
Related lints
- needless_returnunneeded `return` statement
- new_without_defaultChecks for public types with a pub fn new() -> Self method and no implementation of Default
- len_zeroChecks for getting the length of something via .len() just to compare to zero, and suggests using .is_empty() where applicable
- io_other_errorthis can be `std::io::Error::other(_)`
- is_digit_ascii_radixuse of `char::is_digit` with literal radix of 10
- items_after_test_moduleTriggers if an item is declared after the testing module marked with #[cfg(test)]
- iter_next_sliceChecks for usage of iter().next() or iter_mut().next() on a Slice or an Array
- iter_nthcalled `.iter().nth()` on a `Vec`
- iter_nth_zeroChecks for the use of iter.nth(0)
All 847 Clippy lints · Rust compiler errors · Cargo.toml checker
Up next
Related lintclippy::needless_returnunneeded `return` statementRead it next →Did this answer your question?