Clippy lints / Correctness
Clippy lint · Correctness · checked with Clippy 0.1.99
clippy::almost_swapped: Checks for foo = bar; bar = foo sequences
What it meansChecks for foo = bar; bar = foo sequences. It is in the correctness group and denied by default (the build fails).
Does it matter?
This looks like a failed attempt to swap.
Code that is almost certainly wrong. Denied by default: the build fails until you fix it or allow it.
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
a = b;
b = a;
Write this instead
std::mem::swap(&mut a, &mut b);
Turn it off, or on
Allow it where it does not fit your code, as narrowly as you can:
On one item
#[allow(clippy::almost_swapped)]
fn my_function() { /* ... */ }Whole crate (Cargo.toml)
[lints.clippy]
almost_swapped = "allow"One run
cargo clippy -- -A clippy::almost-swappedThe [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 foo = bar; bar = foo sequences.
Why is this bad?
This looks like a failed attempt to swap.
Example
a = b;
b = a;
If swapping is intended, use swap() instead:
std::mem::swap(&mut a, &mut b);
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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