Clippy lints / Restriction
Clippy lint · Restriction · checked with Clippy 0.1.99
clippy::exhaustive_enums: Warns on any exported enums that are not tagged #[non_exhaustive]
What it meansWarns on any exported enums that are not tagged #[non_exhaustive] It is in the restriction group and off by default.
Does it matter?
Making an enum exhaustive is a stability commitment: adding a variant is a breaking change. A project may wish to ensure that there are no exhaustive enums or that every exhaustive enum is explicitly #[allow]ed.
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 (its suggestion may change behaviour, so it only shows it). Change the code by hand:
Flagged
enum Foo {
Bar,
Baz
}
Write this instead
#[non_exhaustive]
enum Foo {
Bar,
Baz
}
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]
exhaustive_enums = "warn"In code
#![warn(clippy::exhaustive_enums)]One run
cargo clippy -- -W clippy::exhaustive-enumsThe [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
Warns on any exported enums that are not tagged #[non_exhaustive]
Why restrict this?
Making an enum exhaustive is a stability commitment: adding a variant is a breaking change.
A project may wish to ensure that there are no exhaustive enums or that every exhaustive
enum is explicitly #[allow]ed.
Example
enum Foo {
Bar,
Baz
}
Use instead:
#[non_exhaustive]
enum Foo {
Bar,
Baz
}
From the Clippy lint list (0.1.99), part of the Rust project, MIT or Apache-2.0. Official entry.
Related lints
- unwrap_usedChecks for .unwrap() or .unwrap_err() calls on Results and .unwrap() call on Options
- module_name_repetitionsDetects public item names that are prefixed or suffixed by the containing public module’s name
- expect_usedChecks for .expect() or .expect_err() calls on Results and .expect() call on Options
- empty_enum_variants_with_bracketsenum variant has empty brackets
- empty_structs_with_bracketsfound empty brackets on struct declaration
- error_impl_errorChecks for types named Error that implement Error
- exhaustive_structsWarns on any exported structs that are not tagged #[non_exhaustive]
- exitDetects calls to the exit() function that are not in the main function
All 847 Clippy lints · Rust compiler errors · Cargo.toml checker
Up next
Related lintclippy::unwrap_usedChecks for .unwrap() or .unwrap_err() calls on Results and .unwrap() call on OptionsRead it next →Did this answer your question?