LaxCow
[](https://github.com/kauppie/laxcow/actions/workflows/rust.yml)
[](https://crates.io/crates/laxcow)
[](https://docs.rs/laxcow/latest/laxcow/)
Clone-on-write smart pointer similar to [Cow](https://doc.rust-lang.org/std/borrow/enum.Cow.html), but with relaxed trait constraints. Crate is totally `no_std`.
## Examples
### Simple usage
```rust
use laxcow::LaxCow;
let lc = LaxCow::Borrowed("foobar");
let lc2 = lc.clone();
assert_eq!(lc2, LaxCow::Borrowed("foobar"));
let owned = lc.into_owned();
assert_eq!(owned, "foobar".to_owned());
```
### Usage not possible with `Cow`
Storing a borrowed struct which doesn't implement [`Clone`](https://doc.rust-lang.org/std/clone/trait.Clone.html).
This is possible because `LaxCow::Owned` variant is not restricted
by the `LaxCow::Borrowed` variant via [`ToOwned`](https://doc.rust-lang.org/std/borrow/trait.ToOwned.html) trait.
```rust
use laxcow::LaxCow;
struct Foo;
// We don't care about the owned type as it is not used.
let laxcow = LaxCow::<_, ()>::Borrowed(&Foo);
```
### `Cow` definition by wrapping `LaxCow`
This example shows the difference between `LaxCow` and `Cow`. It makes `Cow` a struct, but only works here as an example.
```rust
use laxcow::LaxCow;
struct Cow<'a, T: ?Sized + ToOwned>(LaxCow::<'a, T, ::Owned>);
```
## Usability without `alloc`
`LaxCow` can be used without `alloc` but this restricts the usage quite a bit as `ToOwned` is defined in `alloc`.
Interaction with [Cow](https://doc.rust-lang.org/std/borrow/enum.Cow.html) also is not possible. It is also
debatable if clone-on-write functionality is useful in `no_std` environment, but this crate tries not to make
any assumptions about the usage.
## License
Licensed under either of
- Apache License, Version 2.0
([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
- MIT license
([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted
for inclusion in the work by you, as defined in the Apache-2.0 license, shall be
dual licensed as above, without any additional terms or conditions.