better copy assignement default

cpp/includes/Example.hpp

@@ -8,7 +8,7 @@ struct Example {
   virtual ~Example(); // destructor
 
   Example(const Example &);                  // copy constructor
-  Example &operator=(const Example &); // copy assignement
+  const Example &operator=(const Example &); // copy assignement
 };
 
 #endif

cpp/src/Example.cpp

@@ -6,4 +6,10 @@ Example::~Example() {}
 
 Example::Example(const Example &) {}
 
-Example &Example::operator=(const Example &src) { return *this; }
+const Example &Example::operator=(const Example &src) {
+  if (this == &src) {
+    return *this;
+  }
+
+  return *this;
+}