chore: Add course material

397/SolutionEx71ABonus/Subject.h

@@ -0,0 +1,29 @@
+// ======================================================
+// Subject.h
+// ======================================================
+
+#ifndef SUBJECT_H
+#define SUBJECT_H
+
+class Observer;
+
+#include <set>
+
+class Hint {
+  public:
+    virtual ~Hint() {}
+};
+
+class Subject {
+  public:
+    typedef std::set<Observer *> ObsList;
+    void attach(Observer &obs);
+
+  protected:
+    void notify(const Hint &) const;
+
+  private:
+    ObsList myObservers;
+};
+
+#endif