Struct Constant 

pub struct Constant<C>
where
    C: Collection,
    C::Item: View,
{ /* private fields */ }

A statically sized collection that never changes, removes, or adds items.

Constant wraps a collection and provides a stable view collection where elements are identified by their index position. This is useful for static lists of views that don’t need to be updated or reordered.

Implementations

impl<C> Constant<C>

where C: Collection, C::Item: View,

pub const fn new(value: C) -> Self

Creates a new Constant collection from the provided collection.

Parameters

• value - The underlying collection to be wrapped as a constant view collection

Returns

A new Constant instance containing the provided collection

Trait Implementations

impl<C> Clone for Constant<C>

where C: Collection + Clone, C::Item: View,

fn clone(&self) -> Constant<C>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<C> Collection for Constant<C>

where C: Collection + Clone, C::Item: View,

type Item = SelfId<usize>

The type of items stored in the collection.

type Guard = ()

The type of guard returned when registering a watcher.

fn get(&self, index: usize) -> Option<Self::Item>

Gets an item from the collection at the specified index.

fn len(&self) -> usize

Returns the number of items in the collection.

fn watch( &self, _range: impl RangeBounds<usize>, _watcher: impl for<'a> Fn(Context<&'a [Self::Item]>) + 'static, ) -> Self::Guard

Registers a watcher for changes in the specified range of the collection.

fn is_empty(&self) -> bool

Returns true if the collection contains no elements.

impl<C> Debug for Constant<C>

where C: Collection + Debug, C::Item: View,

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<V> Views for Constant<V>

where V: Collection + Clone, V::Item: View,

type Id = SelfId<usize>

The type of unique identifier for items in the collection. Must implement Hash and Ord to ensure uniqueness and ordering.

type Guard = ()

The type of guard returned when registering a watcher.

type View = <V as Collection>::Item

The view type that this collection produces for each element.

fn len(&self) -> usize

Returns the number of items in the collection.

fn get_id(&self, index: usize) -> Option<Self::Id>

Returns the unique identifier for the item at the specified index, or None if out of bounds.

fn get_view(&self, index: usize) -> Option<Self::View>

Returns the view at the specified index, or None if the index is out of bounds.

fn watch( &self, _range: impl RangeBounds<usize>, _watcher: impl for<'a> Fn(Context<&'a [Self::Id]>) + 'static, ) -> Self::Guard

Registers a watcher for changes in the specified range of the collection.

fn is_empty(&self) -> bool

Returns true if the collection contains no elements.