Generic Factory in C++

A generic factory is a factory that can register any class type. It is very easy to write because we are allowed to use void pointers.

#include <functional>

class Factory
{
    public:
        Factory() {}

        ~Factory() {}

        void Register(const std::string _key, const std::function<void *()> _creator)
        {
            m_creators[_key] = _creator;
        }

        template<typename ClassType>
        ClassType* Get(const std::string _key) const
        {
            return static_cast<ClassType *>(m_creators.at(_key)());
        }

    private:
        std::map<std::string, std::function<void *()> > m_creators;
};

Usage:

int main()
{
    Factory f;
    f.Register("Derived1", &BaseClass<Derived1>::CreateInterface);
    f.Register("Derived2", &BaseClass<Derived2>::CreateInterface);
    Derived1 *d1 = f.Get<Derived1>("Derived1");
    Derived2 *d2 = f.Get<Derived2>("Derived2");
    Derived1 *d2 = f.Get<Derived1>("Derived2"); // This also compiles!!!
}

As we are simply casting a void pointer, it is left to the developer to ensure the right class type is passed to Factory::Get function, which might not be the best practice.