factory.h

#ifndef INCLUDE_UTILS_FACTORY_H_
#define INCLUDE_UTILS_FACTORY_H_
#include <glog/logging.h>

#include <functional>
#include <utility>
#include <map>
#define CreateInstance(SubClass, BaseClass) \
  [](void)->BaseClass* {return new SubClass();}

template<typename T>
class Factory{
 //template<Factory<T>> friend class Singleton;
 public:
  void Register(const std::string id, std::function<T*(void)> func);
  T *Create(const std::string id);

 private:
  //<! Map that stores the registered creation functions
  std::map<std::string, std::function<T*(void)>> str2func_;
};

template<typename T>
void Factory<T>::Register(const std::string id,
                                        std::function<T*(void)> func) {
  str2func_[id] = func;
}

template<typename T>
T *Factory<T>::Create(const std::string id) {
  CHECK(str2func_.find(id) != str2func_.end())
      << "The creation function for " << id << " has not been registered";
  return str2func_[id]();
}
#endif // INCLUDE_UTILS_FACTORY_H_