CMake Cookbook

Getting ready

For the following example, we will require a C++ compiler compliant with the C++14 standard or later. The code for this recipe defines a polymorphic hierarchy of animals. We use std::unique_ptr for the base class in the hierarchy:

std::unique_ptr<Animal> cat = Cat("Simon");std::unique_ptr<Animal> dog = Dog("Marlowe);

Instead of explicitly using constructors for the various subtypes, we use an implementation of the factory method. The factory is implemented using C++11 variadic templates. It holds a map of creation functions for each object in the inheritance hierarchy:

typedef std::function<std::unique_ptr<Animal>(const std::string &)> CreateAnimal;

It dispatches them based on a preassigned tag, so that creation of objects ...