Struct widgetry :: tools :: Cached Copy item path

impl<K: PartialEq + Clone, V> Cached<K, V>

pub fn new() -> Cached<K, V>

pub fn key(&self) -> Option<K>

Get the current key.

pub fn value(&self) -> Option<&V>

Get the current value.

pub fn value_mut(&mut self) -> Option<&mut V>

Get the current value, mutably.

pub fn update<F: FnMut(K) -> V>(&mut self, key: Option<K>, produce_value: F)

Update the value if the key has changed.

pub fn set(&mut self, key: K, value: V)

update is preferred, but sometimes produce_value needs to borrow the same struct that owns this Cached. In that case, the caller can manually check key and call this.

pub fn clear(&mut self)

pub fn take(&mut self) -> Option<(K, V)>

Clears the current pair and returns it.

Trait Implementations§

impl<K: PartialEq + Clone, V> Default for Cached<K, V>

fn default() -> Self

Returns the “default value” for a type. Read more

Auto Trait Implementations§

impl<K, V> Freeze for Cached<K, V>
where K: Freeze, V: Freeze,

impl<K, V> RefUnwindSafe for Cached<K, V>
where K: RefUnwindSafe, V: RefUnwindSafe,

impl<K, V> UnwindSafe for Cached<K, V>
where K: UnwindSafe, V: UnwindSafe,

Blanket Implementations§

impl<T> Any for T
where T: 'static + ?Sized,

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more

impl<T> Borrow<T> for T
where T: ?Sized,

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more

impl<T> BorrowMut<T> for T
where T: ?Sized,

fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more

impl<T> Downcast for T
where T: Any,

fn into_any(self: Box<T>) -> Box<dyn Any>

Convert Box<dyn Trait> (where Trait: Downcast) to Box<dyn Any>. Box<dyn Any> can then be further downcast into Box<ConcreteType> where ConcreteType implements Trait.

fn into_any_rc(self: Rc<T>) -> Rc<dyn Any>

Convert Rc<Trait> (where Trait: Downcast) to Rc<Any>. Rc<Any> can then be further downcast into Rc<ConcreteType> where ConcreteType implements Trait.

fn as_any(&self) -> &(dyn Any + 'static)

Convert &Trait (where Trait: Downcast) to &Any. This is needed since Rust cannot generate &Any’s vtable from &Trait’s.

fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)

Convert &mut Trait (where Trait: Downcast) to &Any. This is needed since Rust cannot generate &mut Any’s vtable from &mut Trait’s.

impl<T> DowncastSync for T
where T: Any + Send + Sync,

fn into_any_arc(self: Arc<T>) -> Arc<dyn Any + Sync + Send>

Convert Arc<Trait> (where Trait: Downcast) to Arc<Any>. Arc<Any> can then be further downcast into Arc<ConcreteType> where ConcreteType implements Trait.