Struct Registry

pub struct Registry<T> { /* private fields */ }

A container that can be used for registering values of a given type and retrieving references by handle.

A registry is a centralized container that values can be inserted into and borrowed from. A registry provides several guarantees:

• Arena-based allocated values using an Arena (all references are valid for the lifetime of the container).
• Runtime-checked immutable and mutable borrow rules.
• Values can be borrowed completely independent of one another.

A single value can be moved into the registry using Registry::register, and multiple values can be moved in using Registry::register_extend.

Implementations

impl<T> Registry<T>

pub fn new() -> Self

Creates a new registry.

pub fn with_capacity(size: usize) -> Self

Creates a new registry with the given capacity.

pub fn is_empty(&self) -> bool

Checks if the registry is empty.

pub fn len(&self) -> usize

Returns the number of elements owned by the registry.

pub fn register(&self, value: T) -> Handle

Registers a new value in the arena, returning a handle to that value.

pub fn register_extend<I>(&self, iterable: I) -> (Handle, Handle)

where I: IntoIterator<Item = T>,

Registers the contents of an iterator in the registry.

Returns a numeric range of handles [a, b), where a is the handle of the first element inserted and b is the handle after the last element inserted.

pub fn reserve(&self, additional: usize)

Ensures there is enough continuous space for at least additional values.

pub fn into_vec(self) -> Vec<T>

Converts the Registry<T> into a Vec<T>.

Items will maintain their handle as their vector index.

pub fn iter( &self, ) -> impl Iterator<Item = Result<ElementRef<'_, T>, BorrowError>>

Returns an iterator that provides immutable access to all elements in the registry, in order of registration.

pub fn iter_mut( &mut self, ) -> impl Iterator<Item = Result<ElementRefMut<'_, T>, BorrowError>>

Returns an iterator that provides mutable access to all elements in the registry, in order of registration.

pub fn get_unchecked(&self, handle: Handle) -> ElementRef<'_, T>

Returns a reference to a value previously registered in the registry.

Panics if there is a borrow error.

pub fn get(&self, handle: Handle) -> Result<ElementRef<'_, T>, BorrowError>

Tries to get a reference to a value previously registered in the registry.

pub fn get_mut_unchecked(&self, handle: Handle) -> ElementRefMut<'_, T>

Returns a mutable reference to a value previously registered in the registry.

Panics if there is a borrow error.

pub fn get_mut( &self, handle: Handle, ) -> Result<ElementRefMut<'_, T>, BorrowError>

Tries to get a mutable reference to a value previously registered in the registry.

pub fn safe_to_drop(&mut self) -> bool

Checks if the registry is safe to drop.

A registry is safe to drop if all elements are not borrowed. This check is not thread safe.

Trait Implementations

impl<T: Default> Default for Registry<T>

fn default() -> Registry<T>

Returns the “default value” for a type.