1# yoke [](https://crates.io/crates/yoke) 2 3<!-- cargo-rdme start --> 4 5This crate provides [`Yoke<Y, C>`][Yoke], which allows one to "yoke" (attach) a zero-copy deserialized 6object (say, a [`Cow<'a, str>`](alloc::borrow::Cow)) to the source it was deserialized from, (say, an [`Rc<[u8]>`](alloc::rc::Rc)), 7known in this crate as a "cart", producing a type that looks like `Yoke<Cow<'static, str>, Rc<[u8]>>` 8and can be moved around with impunity. 9 10Succinctly, this allows one to "erase" static lifetimes and turn them into dynamic ones, similarly 11to how `dyn` allows one to "erase" static types and turn them into dynamic ones. 12 13Most of the time the yokeable `Y` type will be some kind of zero-copy deserializable 14abstraction, potentially with an owned variant (like [`Cow`](alloc::borrow::Cow), 15[`ZeroVec`](https://docs.rs/zerovec), or an aggregate containing such types), and the cart `C` will be some smart pointer like 16 [`Box<T>`](alloc::boxed::Box), [`Rc<T>`](alloc::rc::Rc), or [`Arc<T>`](std::sync::Arc), potentially wrapped in an [`Option<T>`](Option). 17 18The key behind this crate is [`Yoke::get()`], where calling [`.get()`][Yoke::get] on a type like 19`Yoke<Cow<'static, str>, _>` will get you a short-lived `&'a Cow<'a, str>`, restricted to the 20lifetime of the borrow used during [`.get()`](Yoke::get). This is entirely safe since the `Cow` borrows from 21the cart type `C`, which cannot be interfered with as long as the `Yoke` is borrowed by [`.get()`](Yoke::get). 22[`.get()`](Yoke::get) protects access by essentially reifying the erased lifetime to a safe local one 23when necessary. 24 25See the documentation of [`Yoke`] for more details. 26 27<!-- cargo-rdme end --> 28 29## More Information 30 31For more information on development, authorship, contributing etc. please visit [`ICU4X home page`](https://github.com/unicode-org/icu4x). 32