+
+LIBMEMCACHED_API
+memcached_return memcached_increment_by_key(memcached_st *ptr,
+ const char *master_key, size_t master_key_length,
+ const char *key, size_t key_length,
+ uint64_t offset,
+ uint64_t *value);
+
+LIBMEMCACHED_API
+memcached_return memcached_decrement_by_key(memcached_st *ptr,
+ const char *master_key, size_t master_key_length,
+ const char *key, size_t key_length,
+ uint64_t offset,
+ uint64_t *value);
+