OxStr

A Rust compact string type that can be either borrowed or reference-counted owned data.

OxStr is conceptually a fusion of Arc<str> and Cow<'a, str>: it allows storing a string slice (&str) or a reference-counted fixed-sized string (Arc<str>), enabling cheap clones of owned data.

It is not relying on an enum but uses an optimized layout, storing only a pointer and a usize length. It relies on a magic bit in the length to know if the value is borrowed or owned. If borrowed, the pointer directly targets the string bytes. If owned, the pointer points to a memory allocation with first the reference counter, then the string bytes.

When owned, cloning is cheap and increments an atomic reference count.

use oxstr::OxStr;

let borrowed = OxStr::new("hello");
let owned = OxStr::new_owned("hello");

assert_eq!(borrowed.as_str(), "hello");
assert_eq!(owned.as_str(), "hello");

There is also a utility method to build a concatenated string in-place:

use oxstr::OxStr;

assert_eq!(OxStr::concat(["foo", " ", "bar"]), "foo bar");

License

This project is licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE or <http://www.apache.org/licenses/LICENSE-2.0>)
• MIT license (LICENSE-MIT or <http://opensource.org/licenses/MIT>)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in oxstr by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.