Return the number of elements equivalent to key.
Declared in <bslstl_unorderedset.h>
unordered_set<KEY, HASH, EQUAL, ALLOCATOR>::size_type
count(key_type const& key) const;Return the number of value_type objects within this unordered set that are equivalent to the specified key. Note that since an unordered set maintains unique keys, the returned value will be either 0 or 1.
0 or 1
| Name | Description |
|---|---|
| key | key value to look up |