# Capacity

The following table provides additional information on the members of this template class.
Member | Description
--- | ---
size_type size() const | Returns: Number of key-value pairs in the table. ### Note This method takes constant time, but is slower than for most STL containers.
bool empty() const | Returns: `size()==0.` ### Note This method takes constant time, but is slower than for most STL containers.
size_type max_size() const | Returns: Inclusive upper bound on number of key-value pairs that the table can hold.
size_type bucket_count() const | Returns: Current number of internal buckets. See method `rehash` for discussion of buckets.

Parent topic: concurrent_hash_map Template Class

## See Also

Hash Policy