pub unsafe extern fn rocksdb_mergeoperator_create(state: *mut c_void, destructor: Option<extern fn(arg1: *mut c_void)>, full_merge: Option<extern fn(arg1: *mut c_void, key: *const c_char, key_length: size_t, existing_value: *const c_char, existing_value_length: size_t, operands_list: *const *const c_char, operands_list_length: *const size_t, num_operands: c_int, success: *mut c_uchar, new_value_length: *mut size_t) -> *mut c_char>, partial_merge: Option<extern fn(arg1: *mut c_void, key: *const c_char, key_length: size_t, operands_list: *const *const c_char, operands_list_length: *const size_t, num_operands: c_int, success: *mut c_uchar, new_value_length: *mut size_t) -> *mut c_char>, delete_value: Option<extern fn(arg1: *mut c_void, value: *const c_char, value_length: size_t)>, name: Option<extern fn(arg1: *mut c_void) -> *const c_char>) -> *mut rocksdb_mergeoperator_t