RS.CLIPPY.PANIC_IN_RESULT_FN

Functions of type `Result<..>` that contain `panic!()` or assertion

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

What it does

Checks for usage of panic! or assertions in a function whose return type is Result.

Why restrict this?

For some codebases, it is desirable for functions of type result to return an error instead of crashing. Hence panicking macros should be avoided.

Known problems

Functions called from a function returning a Result may invoke a panicking macro. This is not checked.

Example

fn result_with_panic() -> Result<bool, String>
{
    panic!("error");
}

Use instead:

fn result_without_panic() -> Result<bool, String> {
    Err(String::from("error"))
}