Expand description
This crate provides Yoke<Y, C>
, which allows one to “yoke” (attach) a zero-copy deserialized
object (say, a Cow<'a, str>
) to the source it was deserialized from, (say, an Rc<[u8]>
),
known in this crate as a “cart”, producing a type that looks like Yoke<Cow<'static, str>, Rc<[u8]>>
and can be moved around with impunity.
Succinctly, this allows one to “erase” static lifetimes and turn them into dynamic ones, similarly
to how dyn
allows one to “erase” static types and turn them into dynamic ones.
Most of the time the yokeable Y
type will be some kind of zero-copy deserializable
abstraction, potentially with an owned variant (like Cow
,
ZeroVec
, or an aggregate containing such types), and the cart C
will be some smart pointer like
Box<T>
, Rc<T>
, or Arc<T>
, potentially wrapped in an Option<T>
.
The key behind this crate is Yoke::get()
, where calling .get()
on a type like
Yoke<Cow<'static, str>, _>
will get you a short-lived &'a Cow<'a, str>
, restricted to the
lifetime of the borrow used during .get()
. This is entirely safe since the Cow
borrows from
the cart type C
, which cannot be interfered with as long as the Yoke
is borrowed by .get()
.
.get()
protects access by essentially reifying the erased lifetime to a safe local one
when necessary.
See the documentation of Yoke
for more details.
Modules§
- Types for optional pointers with niche optimization.
- Types to enable polymorphic carts.
- This module contains helper types for erasing Cart types.
- Workarounds for adding trait bounds to
yoke
objects.
Structs§
- A Cow-like borrowed object “yoked” to its backing data.
Traits§
- This trait marks cart types that do not change source on cloning
- The
Yokeable<'a>
trait is implemented on the'static
version of any zero-copy type; for example,Cow<'static, T>
implementsYokeable<'a>
(for all'a
). One can useYokeable::Output
on this trait to obtain the “lifetime’d” value of theCow<'static, T>
, e.g.<Cow<'static, T> as Yokeable<'a>'>::Output
isCow<'a, T>
.
Derive Macros§
- Custom derive for
yoke::Yokeable
,