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//! [`std::borrow::Cow`]-like enums.
//!
//! # Comparison table
//!
//! | Type | Borrowed | Owned |
//! | -------------------- | -------- | ----------------------- |
//! | [`Cow<'a, T>`] | `&'a T` | `<T as ToOwned>::Owned` |
//! | [`BoxCow<'a, T>`] | `&'a T` | `Box<T>` |
//! | [`SimpleCow<'a, T>`] | `&'a T` | `T` |
//!
//! [`Cow<'a, T>`]: std::borrow::Cow
use std::ops::Deref;
pub enum BoxCow<'a, T: ?Sized> {
Borrowed(&'a T),
Owned(Box<T>),
}
impl<'a, T: ?Sized> BoxCow<'a, T> {
pub fn as_borrowed(&'a self) -> Self {
match self {
BoxCow::Borrowed(v) => BoxCow::Borrowed(v),
BoxCow::Owned(v) => BoxCow::Borrowed(v.as_ref()),
}
}
}
impl<T: ?Sized> Deref for BoxCow<'_, T> {
type Target = T;
fn deref(&self) -> &Self::Target {
match self {
BoxCow::Borrowed(t) => t,
BoxCow::Owned(t) => t,
}
}
}
pub enum SimpleCow<'a, T> {
Borrowed(&'a T),
Owned(T),
}
impl<T> Deref for SimpleCow<'_, T> {
type Target = T;
fn deref(&self) -> &Self::Target {
match self {
SimpleCow::Borrowed(v) => v,
SimpleCow::Owned(v) => v,
}
}
}