RS.CLIPPY.LITERAL_STRING_WITH_FORMATTING_ARGS

Checks if string literals have formatting arguments

This checker is a Clippy lint created by The Rust Project Contributors. The documentation shown here is a copy of the original documentation for: literal_string_with_formatting_args. Copyright ©2025 The Rust Team. All rights reserved.

What it does

Checks if string literals have formatting arguments outside of macros using them (like format!).

Why is this bad?

It will likely not generate the expected content.

Example

let x: Option<usize> = None;
let y = "hello";
x.expect("{y:?}");

Use instead:

let x: Option<usize> = None;
let y = "hello";
x.expect(&format!("{y:?}"));