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//! A module for working with referenced data.
/// A trait for borrowing data from an owned struct
pub trait OwnedToRef {
/// The resulting type referencing back to Self
type Borrowed<'a>
where
Self: 'a;
/// Creates a new object referencing back to the self for storage
fn owned_to_ref(&self) -> Self::Borrowed<'_>;
}
/// A trait for cloning a referenced structure and getting owned objects
///
/// This is the pendant to [`OwnedToRef`]
pub trait RefToOwned<'a> {
/// The resulting type after obtaining ownership.
type Owned: OwnedToRef<Borrowed<'a> = Self>
where
Self: 'a;
/// Creates a new object taking ownership of the data
fn ref_to_owned(&self) -> Self::Owned;
}
impl<T> OwnedToRef for Option<T>
where
T: OwnedToRef,
{
type Borrowed<'a> = Option<T::Borrowed<'a>> where T: 'a;
fn owned_to_ref(&self) -> Self::Borrowed<'_> {
self.as_ref().map(|o| o.owned_to_ref())
}
}
impl<'a, T> RefToOwned<'a> for Option<T>
where
T: RefToOwned<'a> + 'a,
T::Owned: OwnedToRef,
{
type Owned = Option<T::Owned>;
fn ref_to_owned(&self) -> Self::Owned {
self.as_ref().map(|o| o.ref_to_owned())
}
}