Clippy lints / Pedantic
Clippy lint · Pedantic · checked with Clippy 0.1.99
clippy::expl_impl_clone_on_copy: Checks for explicit Clone implementations for Copy types
What it meansChecks for explicit Clone implementations for Copy types. It is in the pedantic group and off by default.
Does it matter?
To avoid surprising behavior, these traits should agree and the behavior of Copy cannot be overridden. In almost all situations a Copy type should have a Clone implementation that does nothing more than copy the object, which is what #[derive(Copy, Clone)] gets you.
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. Change the code by hand:
Flagged
#[derive(Copy)]
struct Foo;
impl Clone for Foo {
// ..
}
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]
expl_impl_clone_on_copy = "warn"In code
#![warn(clippy::expl_impl_clone_on_copy)]One run
cargo clippy -- -W clippy::expl-impl-clone-on-copyThe [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 explicit Clone implementations for Copy
types.
Why is this bad?
To avoid surprising behavior, these traits should
agree and the behavior of Copy cannot be overridden. In almost all
situations a Copy type should have a Clone implementation that does
nothing more than copy the object, which is what #[derive(Copy, Clone)]
gets you.
Example
#[derive(Copy)]
struct Foo;
impl Clone for Foo {
// ..
}
From the Clippy lint list (0.1.99), part of the Rust project, MIT or Apache-2.0. Official entry.
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All 847 Clippy lints · Rust compiler errors · Cargo.toml checker
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