[#bsl-unordered_map-02b-contains-0a]
= xref:bsl.adoc[bsl]::xref:bsl/unordered_map-02b.adoc[unordered_map]::contains
:relfileprefix: ../../
:mrdocs:

Return `true` if this unordered map contains an element whose key is equivalent to the specified `key`.

== Synopses

Declared in `<bslstl_unorderedmap.h>`

Return `true` if this unordered map contains an element whose key is equivalent to the specified `key`.


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
bool
xref:bsl/unordered_map-02b/contains-00.adoc[contains](xref:bsl/unordered_map-02b/key_type.adoc[key_type] const& key) const;
----

[.small]#xref:bsl/unordered_map-02b/contains-00.adoc[_» more..._]#

Return `true` if this unordered map contains an element whose key is equivalent to the specified `key`.


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

[.small]#xref:bsl/unordered_map-02b/contains-0c.adoc[_» more..._]#


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