Trait Emplace

pub trait Emplace<T>: Sized + Deref {
    type Output: Deref<Target = Self::Target>;

    // Required method
    fn try_emplace<N>(n: N) -> Result<Self::Output, <N as TryNew>::Error>
       where N: TryNew<Output = T>;

    // Provided method
    fn emplace<N>(n: N) -> Self::Output
       where N: New<Output = T> { ... }
}

A pointer type that may be “emplaced” as a stable address which a New may be used to construct a value with.

The Emplace<T>::Output type is usually either Self or Pin<Self> depending on the API of Self with respect to [DerefMut].

For example, Arc<T>, Box<T>, and Rc<T> are all Emplace<T, Output = Pin<Self>>.

However, cxx::UniquePtr<T>: Emplace<T, Output = Self>, since cxx::UniquePtr<T> already only allows obtaining pinned mutable references to T due to its more restrictive API, and hence cxx::UniquePtr<T> does not need to be pinned itself.

Required Associated Types

type Output: Deref<Target = Self::Target>

The stable address type within which a value of type T is emplaced.

Required Methods

fn try_emplace<N>(n: N) -> Result<Self::Output, <N as TryNew>::Error>

where N: TryNew<Output = T>,

Constructs a new smart pointer and tries to emplace n into its storage.

Provided Methods

fn emplace<N>(n: N) -> Self::Output

where N: New<Output = T>,

Constructs a new smart pointer and emplaces n into its storage.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl<T> Emplace<T> for Box<T>

type Output = Pin<Box<T>>

fn try_emplace<N>( n: N, ) -> Result<<Box<T> as Emplace<T>>::Output, <N as TryNew>::Error>

where N: TryNew<Output = T>,

impl<T> Emplace<T> for Rc<T>

type Output = Pin<Rc<T>>

fn try_emplace<N>( n: N, ) -> Result<<Rc<T> as Emplace<T>>::Output, <N as TryNew>::Error>

where N: TryNew<Output = T>,

impl<T> Emplace<T> for Arc<T>

type Output = Pin<Arc<T>>

fn try_emplace<N>( n: N, ) -> Result<<Arc<T> as Emplace<T>>::Output, <N as TryNew>::Error>

where N: TryNew<Output = T>,

Implementors

impl<T> Emplace<T> for UniquePtr<T>

where T: MakeCppStorage + UniquePtrTarget,

type Output = UniquePtr<T>