Clippy lint · Complexity · checked with Clippy 0.1.99

clippy::seek_to_start_instead_of_rewind: Checks for jumps to the start of a stream that implements Seek and uses the seek method providing Start as parameter

What it meansChecks for jumps to the start of a stream that implements Seek and uses the seek method providing Start as parameter. It is in the complexity group and warns by default.

Does it matter?

Readability. There is a specific method that was implemented for this exact scenario.

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

fn foo<T: io::Seek>(t: &mut T) {
    t.seek(io::SeekFrom::Start(0));
}

Write this instead

fn foo<T: io::Seek>(t: &mut T) {
    t.rewind();
}

Turn it off, or on

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

On one item

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

Whole crate (Cargo.toml)

[lints.clippy]
seek_to_start_instead_of_rewind = "allow"

One run

cargo clippy -- -A clippy::seek-to-start-instead-of-rewind

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.

Complexitygroup

warndefault level

yesfixed by cargo clippy --fix

1.67.0added in Rust

Clippy's own documentation

What it does

Checks for jumps to the start of a stream that implements Seek and uses the seek method providing Start as parameter.

Why is this bad?

Readability. There is a specific method that was implemented for this exact scenario.

Example

fn foo<T: io::Seek>(t: &mut T) {
    t.seek(io::SeekFrom::Start(0));
}

Use instead:

fn foo<T: io::Seek>(t: &mut T) {
    t.rewind();
}

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

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