Clippy lints / Style
Clippy lint · Style · checked with Clippy 0.1.99
clippy::implicit_saturating_add: manual saturating add detected
What it meansChecks for implicit saturating addition. It is in the style group and warns by default.
What you see
warning: manual saturating add detected --> main.rs:5:1 | 5 | / if u != u32::MAX { 6 | | u += 1; 7 | | } | |_^ help: use instead: `u = u.saturating_add(1);` | = help: for further information visit https://rust-lang.github.io/rust-clippy/stable/index.html#implicit_saturating_add = note: `#[warn(clippy::implicit_saturating_add)]` on by default
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?
The built-in function is more readable and may be faster.
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 mut u:u32 = 7000;
if u != u32::MAX {
u += 1;
}
Write this instead
let mut u:u32 = 7000;
u = u.saturating_add(1);
Turn it off, or on
Allow it where it does not fit your code, as narrowly as you can:
On one item
#[allow(clippy::implicit_saturating_add)]
fn my_function() { /* ... */ }Whole crate (Cargo.toml)
[lints.clippy]
implicit_saturating_add = "allow"One run
cargo clippy -- -A clippy::implicit-saturating-addThe [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 implicit saturating addition.
Why is this bad?
The built-in function is more readable and may be faster.
Example
let mut u:u32 = 7000;
if u != u32::MAX {
u += 1;
}
Use instead:
let mut u:u32 = 7000;
u = u.saturating_add(1);
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
- from_str_radix_10Checks for function invocations of the form primitive::from_str_radix(s, 10)
- get_firstaccessing first element with `x.get(0)`
- if_same_then_elseChecks for if/else with the same body as the then part and the else part
- implicit_saturating_subChecks for implicit saturating subtraction
- inconsistent_digit_groupingdigits grouped inconsistently by underscores
- infallible_destructuring_matchyou seem to be trying to use `match` to destructure a single infallible pattern
All 847 Clippy lints · Rust compiler errors · Cargo.toml checker
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