Trait Update

pub trait Update {
    type Value;

    // Required method
    fn try_maybe_update<U>(
        &self,
        fun: impl FnOnce(&mut Self::Value) -> (bool, U),
    ) -> Option<U>;

    // Provided methods
    fn update(&self, fun: impl FnOnce(&mut Self::Value)) { ... }
    fn maybe_update(&self, fun: impl FnOnce(&mut Self::Value) -> bool) { ... }
    fn try_update<U>(
        &self,
        fun: impl FnOnce(&mut Self::Value) -> U,
    ) -> Option<U> { ... }
}

Updates the value of a signal by applying a function that updates it in place, notifying its subscribers that the value has changed.

Required Associated Types

type Value

The type of the value contained in the signal.

Required Methods

fn try_maybe_update<U>( &self, fun: impl FnOnce(&mut Self::Value) -> (bool, U), ) -> Option<U>

Updates the value of the signal, notifying subscribers if the update function returns (true, _), and returns the value returned by the update function, or None if the signal has already been disposed.

Provided Methods

fn update(&self, fun: impl FnOnce(&mut Self::Value))

Updates the value of the signal and notifies subscribers.

fn maybe_update(&self, fun: impl FnOnce(&mut Self::Value) -> bool)

Updates the value of the signal, but only notifies subscribers if the function returns true.

fn try_update<U>(&self, fun: impl FnOnce(&mut Self::Value) -> U) -> Option<U>

Updates the value of the signal and notifies subscribers, returning the value that is returned by the update function, or None if the signal has already been disposed.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl<T> Update for T

where T: Write,

type Value = <T as Write>::Value