Clippy lints / Pedantic
Clippy lint · Pedantic · checked with Clippy 0.1.99
clippy::naive_bytecount: Checks for naive byte counts
What it meansChecks for naive byte counts It is in the pedantic group and off by default.
Does it matter?
The bytecount crate has methods to count your bytes faster, especially for large slices.
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 count = vec.iter().filter(|x| **x == 0u8).count();
Write this instead
let count = bytecount::count(&vec, 0u8);
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]
naive_bytecount = "warn"In code
#![warn(clippy::naive_bytecount)]One run
cargo clippy -- -W clippy::naive-bytecountThe [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 naive byte counts
Why is this bad?
The bytecount
crate has methods to count your bytes faster, especially for large slices.
Known problems
If you have predominantly small slices, the
bytecount::count(..) method may actually be slower. However, if you can
ensure that less than 2³²-1 matches arise, the naive_count_32(..) can be
faster in those cases.
Example
let count = vec.iter().filter(|x| **x == 0u8).count();
Use instead:
let count = bytecount::count(&vec, 0u8);
From the Clippy lint list (0.1.99), part of the Rust project, MIT or Apache-2.0. Official entry.
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All 847 Clippy lints · Rust compiler errors · Cargo.toml checker
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