dyn-clone (1.0.20)

Published 2026-03-26 10:57:26 +00:00 by siennathesane

Set up this registry in the Cargo configuration file (for example ~/.cargo/config.toml):

[registry]
default = "gitea"

[registries.gitea]
index = "sparse+" # Sparse index
# index = "" # Git

[net]
git-fetch-with-cli = true

To install the package using Cargo, run the following command:

cargo add dyn-clone@1.0.20

For more information on the Cargo registry, see the documentation.

Clone trait that is dyn-compatible

This crate provides a DynClone trait that can be used in trait objects, and a clone_box function that can clone any sized or dynamically sized implementation of DynClone. Types that implement the standard library's std::clone::Clone trait are automatically usable by a DynClone trait object.

The signature of clone_box is:

fn clone_box<T>(t: &T) -> Box<T>
where
    T: ?Sized + DynClone

Example

use dyn_clone::DynClone;

trait MyTrait: DynClone {
    fn recite(&self);
}

impl MyTrait for String {
    fn recite(&self) {
        println!("{} ♫", self);
    }
}

fn main() {
    let line = "The slithy structs did gyre and gimble the namespace";

    // Build a trait object holding a String.
    // This requires String to implement MyTrait and std::clone::Clone.
    let x: Box<dyn MyTrait> = Box::new(String::from(line));

    x.recite();

    // The type of x2 is a Box<dyn MyTrait> cloned from x.
    let x2 = dyn_clone::clone_box(&*x);

    x2.recite();
}

This crate includes a macro for generating the implementation impl std::clone::Clone for Box<dyn MyTrait> in terms of dyn_clone::clone_box:

// As before.
trait MyTrait: DynClone {
    /* ... */
}

dyn_clone::clone_trait_object!(MyTrait);

// Now data structures containing Box<dyn MyTrait> can derive Clone:
#[derive(Clone)]
struct Container {
    trait_object: Box<dyn MyTrait>,
}

License

^{Licensed under either of Apache License, Version
2.0 or MIT license at your option.}
_{Unless you explicitly state otherwise, any contribution intentionally submitted
for inclusion in this crate by you, as defined in the Apache-2.0 license, shall
be dual licensed as above, without any additional terms or conditions.}

ID	Version
rustversion	^1.0
trybuild	^1.0.66

dyn clone trait-object object-safe

Details

Cargo

2026-03-26 10:57:26 +00:00

David Tolnay <dtolnay@gmail.com>

Repository Site

Documentation Site

MIT OR Apache-2.0

12 KiB

Assets (1)

dyn-clone-1.0.20.crate 12 KiB

Versions (1) View all

1.0.20

2026-03-26

dyn-clone (1.0.20)

Installation

About this package

Clone trait that is dyn-compatible

Example

License

Dependencies

Keywords