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ParamState

Struct ParamState

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

Expand description

The parameters of one composable call, kept in a slot between recompositions so the call can skip its body when they are unchanged. Generated by the #[composable] macro.

Implementations§

impl<T> ParamState<T>

pub fn update_fields( &mut self, fresh: impl FnOnce() -> T, refresh: impl FnOnce(&mut T) -> bool, ) -> bool

Brings a call’s stored parameters up to date: fresh stores them on the call’s first composition, and refresh updates each stored field that differs and says whether any did. Unchanged fields are not cloned again.

pub fn value(&self) -> Option<T>
where T: Clone,

Returns a clone of the stored parameters, or None before any composition stored them.

Trait Implementations§

impl<T> Default for ParamState<T>

fn default() -> Self

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

Auto Trait Implementations§

impl<T> Freeze for ParamState<T>
where Option<T>: Freeze,

impl<T> RefUnwindSafe for ParamState<T>
where Option<T>: RefUnwindSafe,

impl<T> Send for ParamState<T>
where Option<T>: Send,

impl<T> Sync for ParamState<T>
where Option<T>: Sync,

impl<T> Unpin for ParamState<T>
where Option<T>: Unpin,

impl<T> UnsafeUnpin for ParamState<T>
where Option<T>: UnsafeUnpin,

impl<T> UnwindSafe for ParamState<T>
where Option<T>: 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> From<T> for T

fn from(t: T) -> T

Returns the argument unchanged.

impl<T, U> Into<U> for T
where U: From<T>,

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

impl<T, U> TryFrom<U> for T
where U: Into<T>,

type Error = !

The type returned in the event of a conversion error.

fn try_from(value: U) -> Result<T, !>

Performs the conversion.

impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.