OrderEvent

OrderEvent packages a single change in an order’s lifecycle and can forward itself to any OrderExecutionListener via dispatchTo().

enum class OrderEventType {
  ACCEPTED, PARTIALLY_FILLED, FILLED,
  CANCELED, EXPIRED, REJECTED, REPLACED
};

struct OrderEvent {
  OrderEventType type;
  Order          order;        // original order
  Order          newOrder;     // for REPLACED
  Quantity       fillQty;      // for PARTIALLY_FILLED
  std::string    rejectionReason;
  uint64_t       tickSequence; // filled by EventBus
};

Fields

Field	Used in event type(s)	Meaning
type	all	Kind of lifecycle transition.
order	all	Order being updated.
newOrder	REPLACED	Replacement order.
fillQty	PARTIALLY_FILLED	Quantity filled in this partial.
rejectionReason	REJECTED	Text reason from exchange / risk checks.
tickSequence	all	Monotonic ID injected by EventBus.

dispatchTo()

template <typename ListenerT>
void dispatchTo(ListenerT& l) const {
  switch (type) {
    case OrderEventType::ACCEPTED:         l.onOrderAccepted(order);                 break;
    case OrderEventType::PARTIALLY_FILLED: l.onOrderPartiallyFilled(order, fillQty); break;
    case OrderEventType::FILLED:           l.onOrderFilled(order);                   break;
    case OrderEventType::CANCELED:         l.onOrderCanceled(order);                 break;
    case OrderEventType::EXPIRED:          l.onOrderExpired(order);                  break;
    case OrderEventType::REJECTED:         l.onOrderRejected(order, rejectionReason);break;
    case OrderEventType::REPLACED:         l.onOrderReplaced(order, newOrder);       break;
  }
}

Compile-time guarded by static_assert(concepts::OrderExecutionListener<ListenerT>) to ensure the listener implements every callback.

Purpose

• Provide a single, strongly-typed object for all order-execution notifications.
• Allow EventBus to deliver the event generically while each listener handles the specifics through dispatchTo().