clippy::negative_feature_names: Checks for negative feature names with prefix no- or not-

What it meansChecks for negative feature names with prefix no- or not- It is in the cargo group and off by default.

Does it matter?

Features are supposed to be additive, and negatively-named features violate it.

Checks on Cargo.toml metadata. Off by default.

How to fix it

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

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]
negative_feature_names = "warn"

In code

#![warn(clippy::negative_feature_names)]

One run

cargo clippy -- -W clippy::negative-feature-names

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.

Cargogroup

allowdefault level

nofixed by cargo clippy --fix

1.57.0added in Rust

Clippy's own documentation

What it does

Checks for negative feature names with prefix no- or not-

Why is this bad?

Features are supposed to be additive, and negatively-named features violate it.

Example

[features]
default = []
no-abc = []
not-def = []

Use instead:

[features]
default = ["abc", "def"]
abc = []
def = []

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

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