Trait PostageWatchSenderExt 

pub trait PostageWatchSenderExt<T> {
    // Required methods
    fn try_maybe_send<F, E>(&mut self, update: F) -> Result<(), E>
       where T: PartialEq,
             F: FnOnce(&T) -> Result<T, E>;
    fn maybe_send<F>(&mut self, update: F)
       where T: PartialEq,
             F: FnOnce(&T) -> T;
}

Extension trait for some postage::watch::Sender to provide maybe_send

Ideally these, or something like them, would be upstream: See https://github.com/austinjones/postage-rs/issues/56.

We provide this as an extension trait became the implementation is a bit fiddly. This lets us concentrate on the actual logic, when we use it.

Required Methods

fn try_maybe_send<F, E>(&mut self, update: F) -> Result<(), E>

where T: PartialEq, F: FnOnce(&T) -> Result<T, E>,

Update, by calling a fallible function, sending only if necessary

Calls update on the current value in the watch, to obtain a new value. If the new value doesn’t compare equal, updates the watch, notifying receivers.

fn maybe_send<F>(&mut self, update: F)

where T: PartialEq, F: FnOnce(&T) -> T,

Update, by calling a function, sending only if necessary

Calls update on the current value in the watch, to obtain a new value. If the new value doesn’t compare equal, updates the watch, notifying receivers.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementations on Foreign Types

impl<T> PostageWatchSenderExt<T> for Sender<T>

Extension trait for some postage::watch::Sender to provide maybe_send

Ideally these, or something like them, would be upstream: See https://github.com/austinjones/postage-rs/issues/56.

We provide this as an extension trait became the implementation is a bit fiddly. This lets us concentrate on the actual logic, when we use it.

fn try_maybe_send<F, E>(&mut self, update: F) -> Result<(), E>

where T: PartialEq, F: FnOnce(&T) -> Result<T, E>,

Update, by calling a fallible function, sending only if necessary

Calls update on the current value in the watch, to obtain a new value. If the new value doesn’t compare equal, updates the watch, notifying receivers.

fn maybe_send<F>(&mut self, update: F)

where T: PartialEq, F: FnOnce(&T) -> T,

Update, by calling a function, sending only if necessary

Calls update on the current value in the watch, to obtain a new value. If the new value doesn’t compare equal, updates the watch, notifying receivers.

Implementors