[#bsl-unordered_set-02a-count-00]
= xref:bsl.adoc[bsl]::xref:bsl/unordered_set-02a.adoc[unordered_set<ManagedAttribute, AttributeHash>]::count
:relfileprefix: ../../
:mrdocs:

`count` overloads

== Synopses

Declared in `<bslstl_unorderedset.h>`

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.


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
xref:bsl/unordered_set-02a/size_type.adoc[size_type]
xref:bsl/unordered_set-02a/count-01.adoc[count](xref:bsl/unordered_set-02a/key_type.adoc[key_type] const& key) const;
----

[.small]#xref:bsl/unordered_set-02a/count-01.adoc[_» more..._]#

Return the number of `value_type` objects within this unordered set that are equivalent to the specified `key`. The behavior is undefined unless `key` is equivalent to at most one element in this unordered set. Note that since an unordered set maintains unique keys, the returned value will be either 0 or 1.


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
template<class LOOKUP_KEY>
xref:bsl/unordered_set-02a/size_type.adoc[size_type]
xref:bsl/unordered_set-02a/count-0a.adoc[count](LOOKUP_KEY const& key) const
requires BloombergLP::bslmf::IsTransparentPredicate<HASH, LOOKUP_KEY>::value
        && BloombergLP::bslmf::IsTransparentPredicate<EQUAL,LOOKUP_KEY>::value;
----

[.small]#xref:bsl/unordered_set-02a/count-0a.adoc[_» more..._]#


[.small]#Created with https://www.mrdocs.com[MrDocs]#