bind¶

Called once when the reaction is created (at the .then() call site). Use this to register the reaction with event sources.

Signature¶

template <typename DSL>
static void bind(const std::shared_ptr<threading::Reaction>& reaction, Args... args)

Details¶

Aspect	Detail
When	Reaction registration time (inside `.then()`)
Thread	Main thread during construction, or whichever thread calls `on<>().then()` at runtime
Returns	`void` (return values are discarded)
Fusion	All words with `bind` are called sequentially. Runtime arguments (from `on<>(args...)`) are consumed left-to-right by whichever word's `bind` accepts them.

Context & Arguments¶

reaction — the newly created Reaction object. Store a reference to it in whatever event registry you need (e.g., TypeCallbackStore, a timer queue, an IO poll set).
args... — runtime arguments passed to on<>(...). For example, on<IO>(fd, IO::READ) passes the file descriptor and event mask. Arguments are consumed greedily left-to-right across all words that have bind with matching parameters.

The thread context is typically the main thread during reactor construction. However, if on<>().then() is called at runtime (e.g., inside another reaction's callback), it runs on whichever thread the calling reaction is executing on.

Example¶

struct Trigger {
    template <typename DSL>
    static void bind(const std::shared_ptr<threading::Reaction>& reaction) {
        // Register this reaction to be notified when T is emitted
        store::TypeCallbackStore<T>::add(reaction);
    }
};

Built-in Words Using bind¶

Trigger<T> — registers in TypeCallbackStore<T>
Every — submits a ChronoTask to ChronoController
IO — registers a file descriptor with IOController
Watchdog — submits a deadline task to ChronoController
Network<T> — registers type hash with NetworkController