Clean up CMakeLists in all C++ examples

+ Rename output executables to match directory structure
+ Remove libraries for small examples
+ Supress -Wreturn-type warnings for singleton that is intentionally not copyable

cpp/patterns/factory/abstract-factory.hpp

@@ -0,0 +1,33 @@
+
+#ifndef FACTORY_HPP
+#define FACTORY_HPP
+
+#include <array>
+#include <string>
+#include <unordered_map>
+#include <utility>
+#include <vector>
+
+#include "parts.hpp"
+
+// Gear Concrete Factory
+class GearFactory {
+public:
+  explicit GearFactory(std::string name_="GearFactory") :
+      name(std::move(name_)) {}
+
+  Part* requestPart();
+  Part* requestPart(std::string partName, float price);
+  void showStock() const;
+  std::string getName() const { return name;}
+
+protected:
+  Part* makePart();
+  Part* makePart(std::string name, float price);
+
+private:
+  std::string name;
+  std::unordered_map<std::string, int> inventory;
+};
+
+#endif // FACTORY_HPP