Clippy lint · Restriction · checked with Clippy 0.1.99

clippy::error_impl_error: Checks for types named Error that implement Error

What it meansChecks for types named Error that implement Error. It is in the restriction group and off by default.

Does it matter?

It can become confusing when a codebase has 20 types all named Error, requiring either aliasing them in the use statement or qualifying them like my_module::Error. This hinders comprehension, as it requires you to memorize every variation of importing Error used across a codebase.

Lints that forbid language features for specific codebases (no unwrap, no indexing...). Off by default; pick them one by one, never the whole group.

How to fix it

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

Flagged

#[derive(Debug)]
pub enum Error { ... }

impl std::fmt::Display for Error { ... }

impl std::error::Error for Error { ... }

Turn it off, or on

It is off by default. To use it, set it to warn or deny:

Whole crate (Cargo.toml)

[lints.clippy]
error_impl_error = "warn"

In code

#![warn(clippy::error_impl_error)]

One run

cargo clippy -- -W clippy::error-impl-error

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.

Restrictiongroup

allowdefault level

nofixed by cargo clippy --fix

1.73.0added in Rust

Clippy's own documentation

What it does

Checks for types named Error that implement Error.

Why restrict this?

It can become confusing when a codebase has 20 types all named Error, requiring either aliasing them in the use statement or qualifying them like my_module::Error. This hinders comprehension, as it requires you to memorize every variation of importing Error used across a codebase.

Example

#[derive(Debug)]
pub enum Error { ... }

impl std::fmt::Display for Error { ... }

impl std::error::Error for Error { ... }

From the Clippy lint list (0.1.99), part of the Rust project, MIT or Apache-2.0. Official entry.

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