Clippy lints / Pedantic
Clippy lint · Pedantic · checked with Clippy 0.1.99
clippy::match_wildcard_for_single_variants: Checks for wildcard enum matches for a single variant
What it meansChecks for wildcard enum matches for a single variant. It is in the pedantic group and off by default.
Does it matter?
New enum variants added by library updates can be missed.
Stricter lints with some false positives. Off by default; opt in with clippy::pedantic.
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
match x {
Foo::A => {},
Foo::B => {},
_ => {},
}
Write this instead
match x {
Foo::A => {},
Foo::B => {},
Foo::C => {},
}
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]
match_wildcard_for_single_variants = "warn"In code
#![warn(clippy::match_wildcard_for_single_variants)]One run
cargo clippy -- -W clippy::match-wildcard-for-single-variantsThe [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
Checks for wildcard enum matches for a single variant.
Why is this bad?
New enum variants added by library updates can be missed.
Known problems
Suggested replacements may not use correct path to enum if it’s not present in the current scope.
Example
match x {
Foo::A => {},
Foo::B => {},
_ => {},
}
Use instead:
match x {
Foo::A => {},
Foo::B => {},
Foo::C => {},
}
From the Clippy lint list (0.1.99), part of the Rust project, MIT or Apache-2.0. Official entry.
Related lints
- too_many_linesChecks for functions with a large amount of lines
- missing_errors_docChecks the doc comments of publicly visible functions that return a Result type and warns if there is no # Errors section
- must_use_candidateChecks for public functions that have no #[must_use] attribute, but return something not already marked must-use, have no mutable arg and mutate no statics
- match_boolChecks for matches where match expression is a bool
- match_same_armsChecks for match with identical arm bodies. Note: Does not lint on wildcards if the non_exhaustive_omitted_patterns_lint feature is enabled and disallowed
- match_wild_err_arm`Err(_)` matches all errors
- maybe_infinite_iterChecks for iteration that may be infinite
- mismatching_type_param_order`Foo` has a similarly named generic type parameter `B` in its declaration, but in a different order
All 847 Clippy lints · Rust compiler errors · Cargo.toml checker
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