macro_subject_derive

Helper macro to implement a few traits required for a subject.

Traits you still have to implement to get a subject

• Observable
• Observer (unless using #[rx_delegate_observer_to_destination])
• SubscriptionLike (unless using #[rx_delegate_subscription_like_to_destination])

Traits Implemented

• WithPrimaryCategory: Sets the associated type to PrimaryCategorySubject
• ObserverInput: Sets the associated type In to the value of the #[rx_in(...)] attribute, or to Never (Infallible) if missing. Also sets the associated InError type to the value of the #[rx_in_error(...)] attribute, or to Never if missing.
• ObservableOutput: Sets the associated type Out to the value of the #[rx_out(...)] attribute, or to Never (Infallible) if missing. Also sets the associated OutError type to the value of the #[rx_out_error(...)] attribute, or to Never if missing.
• UpgradeableObserver: By default. It implements UpgradeableObserver by wrapping the subject into a ObserverSubscriber. This implementation can be opted out with the #[rx_does_not_upgrade_to_observer_subscriber] attribute to provide a manual implementation. Other preset implementations can be used with the #[rx_upgrades_to(...)] attribute.

Attributes

All attributes are prefixed with rx_ for easy auto-complete access.

• #[rx_in(...)] (optional, default: Never): Defines the input type of the subject
• #[rx_in_error(...)] (optional, default: Never): Defines the input error type of the subject
• #[rx_out(...)] (optional, default: Never): Defines the output type of the subject, usually it's the same as the input type
• #[rx_out_error(...)] (optional, default: Never): Defines the output error type of the subject, usually it's the same as the input error type
• #[rx_does_not_upgrade_to_observer_subscriber] (optional): Opts out the default UpgradeableObserver implementation which just wraps the Subject in a ObserverSubscriber when used as a destination for an Observable to prevent upstream from unsubscribing the entire Subject.
• #[rx_upgrades_to(...)] (optional, accepts: self, observer_subscriber): Defines a preset implementation for UpgradeableObserver
  • self: Upgraded version is itself, causing it to be unsubscribed when upstream is unsubscribed when used as an observables destination.
  • observer_subscriber: Upgraded version is itself wrapped in ObserverSubscriber, causing it to not be unsubscribed when upstream is unsubscribed when used as an observables destination.
• #[rx_delegate_subscription_like_to_destination] (optional): Opts into the trivial implementation of SubscriptionLike where the traits methods are just simply called on the field marked as #[destination].
• #[rx_delegate_observer_to_destination] (optional): Opts into the trivial implementation of Observer where the traits methods are just simply called on the field marked as #[destination].

See Also

• RxExecutor - Derive macro for Executors.
• RxObservable - Derive macro for Observables.
• RxObserver - Derive macro for RxObservers.
• RxOperator - Derive macro for Operators.
• RxScheduler - Derive macro for Schedulers.
• RxSubscriber - Derive macro for Subscribers.
• RxSubscription - Derive macro for Subscriptions.
• RxWork - Derive macro for schedulable work.

Expanding the proc macro

In case you want to inspect the output of the proc macro.

If you haven't installed cargo-expand yet, install it first:

cargo install cargo-expand

Then expand the macro output:

cargo expand -p rx_core_observable_interval