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30 
31 #ifndef OPENCV_FLANN_OBJECT_FACTORY_H_
32 #define OPENCV_FLANN_OBJECT_FACTORY_H_
33 
34 #include <map>
35 
36 namespace cvflann
37 {
38 
39 class CreatorNotFound
40 {
41 };
42 
43 template<typename BaseClass,
44          typename UniqueIdType,
45          typename ObjectCreator = BaseClass* (*)()>
46 class ObjectFactory
47 {
48     typedef ObjectFactory<BaseClass,UniqueIdType,ObjectCreator> ThisClass;
49     typedef std::map<UniqueIdType, ObjectCreator> ObjectRegistry;
50 
51     // singleton class, private constructor
ObjectFactory()52     ObjectFactory() {}
53 
54 public:
55 
subscribe(UniqueIdType id,ObjectCreator creator)56     bool subscribe(UniqueIdType id, ObjectCreator creator)
57     {
58         if (object_registry.find(id) != object_registry.end()) return false;
59 
60         object_registry[id] = creator;
61         return true;
62     }
63 
unregister(UniqueIdType id)64     bool unregister(UniqueIdType id)
65     {
66         return object_registry.erase(id) == 1;
67     }
68 
create(UniqueIdType id)69     ObjectCreator create(UniqueIdType id)
70     {
71         typename ObjectRegistry::const_iterator iter = object_registry.find(id);
72 
73         if (iter == object_registry.end()) {
74             throw CreatorNotFound();
75         }
76 
77         return iter->second;
78     }
79 
instance()80     static ThisClass& instance()
81     {
82         static ThisClass the_factory;
83         return the_factory;
84     }
85 private:
86     ObjectRegistry object_registry;
87 };
88 
89 }
90 
91 #endif /* OPENCV_FLANN_OBJECT_FACTORY_H_ */
92