clippy::suspicious_assignment_formatting: this looks like you are trying to use `.. -= ..`, but you really are doing `.. = (- ..)`

What you see

warning: this looks like you are trying to use `.. -= ..`, but you really are doing `.. = (- ..)`
 --> main.rs:3:2
  |
3 | a =- 42; // confusing, should it be `a -= 42` or `a = -42`?
  |  ^^^^
  |
  = note: to remove this lint, use either `-=` or `= -`
  = help: for further information visit https://rust-lang.github.io/rust-clippy/stable/index.html#suspicious_assignment_formatting
  = note: `#[warn(clippy::suspicious_assignment_formatting)]` 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?

This is either a typo of *=, != or -= or confusing.

Code that is most likely wrong or useless. Warns by default.

How to fix it

Clippy does not fix this one automatically. Change the code by hand:

Flagged

a =- 42; // confusing, should it be `a -= 42` or `a = -42`?

Turn it off, or on

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

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

[lints.clippy]
suspicious_assignment_formatting = "allow"

cargo clippy -- -A clippy::suspicious-assignment-formatting

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.