Minor cleanups.

Author: juanchopanza

Concurrency/Queue/ExceptionUnsafeQueue.h

@@ -9,7 +9,7 @@ void produce(Queue<int>& q) {
 }
 
 void consume(Queue<int>& q, unsigned int id) {
-  for (int i = 0; i< 10000; ++i) {
+  for (int i = 0; i< 2500; ++i) {
     auto item = q.pop();
     std::cout << "Consumer " << id << " popped " << item << "\n";
   }

Concurrency/Queue/producer_consumer1.cpp

@@ -16,6 +16,12 @@ class Subject
   {
     observers_[event].push_back(std::forward<Observer>(observer));
   }
+  template <typename Observer>
+  void registerObserver(Event&& event, Observer&& observer)
+  {
+    observers_[std::move(event)].push_back(std::forward<Observer>(observer));
+  }
+
   void notify(const Event& event) const
   {
     for (const auto& obs : observers_.at(event)) obs();