pub enum EitherCart<C0, C1> {
    A(C0),
    B(C1),
}
Expand description

A cart that can be one type or the other. Enables ergonomic polymorphic carts.

EitherCart enables yokes originating from different data sources and therefore having different cart types to be merged into the same yoke type, but still being able to recover the original cart type if necessary.

All relevant Cart traits are implemented for EitherCart, and carts can be safely wrapped in an EitherCart.

Also see Yoke::erase_box_cart().

Examples

use std::borrow::Cow;
use std::rc::Rc;
use yoke::either::EitherCart;
use yoke::Yoke;

let y1: Yoke<&'static str, Rc<str>> =
    Yoke::attach_to_zero_copy_cart("reference counted hello world".into());

let y2: Yoke<&'static str, &str> = Yoke::attach_to_zero_copy_cart("borrowed hello world");

type CombinedYoke<'a> = Yoke<&'static str, EitherCart<Rc<str>, &'a str>>;

// Both yokes can be combined into a single yoke type despite different carts
let y3: CombinedYoke = y1.wrap_cart_in_either_a();
let y4: CombinedYoke = y2.wrap_cart_in_either_b();

assert_eq!(*y3.get(), "reference counted hello world");
assert_eq!(*y4.get(), "borrowed hello world");

// The resulting yoke is cloneable if both cart types implement CloneableCart
let y5 = y4.clone();
assert_eq!(*y5.get(), "borrowed hello world");

Variants

A(C0)

B(C1)

Trait Implementations

Returns a copy of the value. Read more
Performs copy-assignment from source. Read more
The resulting type after dereferencing.
Dereferences the value.
This method tests for self and other values to be equal, and is used by ==. Read more
This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
Uses borrowed data to replace owned data, usually by cloning. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.