rust-lang / rust-lang/rust-clippy

Prefer `vec.truncate(x)` over `vec.drain(x..)`

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A-lint
Dominant language
Rust
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Description

What it does

Suggest to replace vec.drain(x..) to vec.truncate(x) since it is simpler and cleaner.

Advantage
  • It is shorter and cleaner
Drawbacks

No response

Example
fn main() {
    let mut x = vec![1, 2, 3, 4, 5, 6];
    x.drain(1..);
}

Could be written as:

fn main() {
    let mut x = vec![1, 2, 3, 4, 5, 6];
    x.truncate(1);
}

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

The issue names no files or tests. Start by locating Clippy's existing lint and test conventions for Vec method suggestions, then compare the drain(1..) and truncate(1) examples. Done means the requested pattern produces the intended suggestion and is covered by appropriate tests.

Written by the indexing model from the issue text.

Assessment

Tech stack
rust
Domain
tooling
Issue type
Feature
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
48/100

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