Struct widgetry::Cached [−][src]
Expand description
Store a cached key/value pair, only recalculating when the key changes.
Fields
contents: Option<(K, V)>
Implementations
Update the value if the key has changed.
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.
Trait Implementations
Auto Trait Implementations
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
Mutably borrows from an owned value. Read more
impl<T> Downcast for T where
T: Any,
impl<T> Downcast for T where
T: 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
. Read more
pub fn into_any_rc(self: Rc<T>) -> Rc<dyn Any + 'static>
pub fn into_any_rc(self: Rc<T>) -> Rc<dyn Any + 'static>
Convert Rc<Trait>
(where Trait: Downcast
) to Rc<Any>
. Rc<Any>
can then be
further downcast
into Rc<ConcreteType>
where ConcreteType
implements Trait
. Read more
Convert &Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &Any
’s vtable from &Trait
’s. Read more
pub fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
pub 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. Read more
type Output = T
type Output = T
Should always be Self