Add factory example

cpp/patterns/factory/main.cpp

@@ -0,0 +1,24 @@
+
+#include <array>
+#include <cstdlib>
+#include <iostream>
+#include <vector>
+
+#include "factory.hpp"
+
+int main(const int argc, const char * argv[]) {
+  // Testing GearFactory
+  GearFactory gearFactory;
+  const int gearsRequired = 5;
+
+  std::cout << "Testing " << gearFactory.getName() <<"...\nMaking 5 Gears...\n";
+  for (int i = 0; i < gearsRequired; i++) gearFactory.requestPart();
+  std::cout << std::endl << gearFactory.getName() << " inventory:\n";
+  gearFactory.showStock();
+
+  // Making custom gears
+  for (int i = 0; i < gearsRequired; i++) gearFactory.requestPart("Big Gear", 2.5f);
+  std::cout << std::endl << gearFactory.getName() << " inventory:\n";
+  gearFactory.showStock();
+
+}