using H5I_REGISTER. The second parameter is a hid_t and is the ID of the object to be tested. The last parameter is a void *. This is the
key parameter and can be used however the user finds helpful, or it can be ignored if it is not needed.
func returns 0 if the object it is testing does not pass its criteria. A non-zero value should be returned if the object does pass its criteria.
H5I_search__func_t is defined in H5Ipublic.h and is shown below.
typedef int (*H5I_search_func_t)(void *obj, hid_t id, void *key);
key parameter will be passed to the search function as a parameter. It can be used to further define the search at run-time.
Programming Note for C++ Developers Using C Functions:
If a C routine that takes a function pointer as an argument is called from within C++ code, the C routine should be returned from normally.
Examples of this kind of routine include callbacks such