[#BloombergLP-bdlc-FlatHashMap-at-0f]
= xref:BloombergLP.adoc[BloombergLP]::xref:BloombergLP/bdlc.adoc[bdlc]::xref:BloombergLP/bdlc/FlatHashMap.adoc[FlatHashMap]::at
:relfileprefix: ../../../
:mrdocs:

Return a modifiable reference to the mapped value for `key`&period;

== Synopsis

Declared in `&lt;bdlc&lowbar;flathashmap&period;h&gt;`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
template&lt;class LOOKUP&lowbar;KEY&gt;
VALUE&
at(LOOKUP&lowbar;KEY const& key)
requires BloombergLP&colon;&colon;bslmf&colon;&colon;IsTransparentPredicate&lt;HASH, LOOKUP&lowbar;KEY&gt;&colon;&colon;value
         &amp;&amp; BloombergLP&colon;&colon;bslmf&colon;&colon;IsTransparentPredicate&lt;EQUAL,LOOKUP&lowbar;KEY&gt;&colon;&colon;value;
----

== Description

Return a reference providing modifiable access to the mapped value associated with a key that is equivalent to the specified `key` in this map, if such an entry exists&semi; otherwise throw a `std&colon;&colon;out&lowbar;of&lowbar;range` exception&period; Note that this method is not exception&hyphen;neutral&period;

== Return Value

modifiable reference to the mapped value for `key`

== Parameters

[cols="1,4"]
|===
| Name| Description
| *key*
| transparent key whose mapped value is accessed
|===


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