KEYWORD_IDENTS_2024 in rustc_lint::builtin - Rust
Description: The `keyword_idents_2024` lint detects edition keywords being used as an identifier.

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## KEYWORD_IDENTS_2024

# Static KEYWORD_IDENTS_2024

Source

    pub static KEYWORD_IDENTS_2024: &Lint

Expand description

The `keyword_idents_2024` lint detects edition keywords being used as an identifier.

#### §Example

ⓘ

    #![deny(keyword_idents_2024)]
    // edition 2015
    fn gen() {}

{{produces}}

#### §Explanation

Rust editions allow the language to evolve without breaking backwards compatibility. This lint catches code that uses new keywords that are added to the language that are used as identifiers (such as a variable name, function name, etc.). If you switch the compiler to a new edition without updating the code, then it will fail to compile if you are using a new keyword as an identifier.

You can manually change the identifiers to a non-keyword, or use a raw identifier, for example `r#gen`, to transition to a new edition.

This lint solves the problem automatically. It is “allow” by default because the code is perfectly valid in older editions. The `cargo fix` tool with the `--edition` flag will switch this lint to “warn” and automatically apply the suggested fix from the compiler (which is to use a raw identifier). This provides a completely automated way to update old code for a new edition.