[#BloombergLP-bdlc-FlatHashMap-operator_subs-06] = xref:BloombergLP.adoc[BloombergLP]::xref:BloombergLP/bdlc.adoc[bdlc]::xref:BloombergLP/bdlc/FlatHashMap.adoc[FlatHashMap]::operator[] :relfileprefix: ../../../ :mrdocs: Return a reference providing modifiable access to the mapped value associated with the specified `key` in this map. If this map does not already contain an element having `key`, insert an element with the `key` and a default‐constructed `VALUE`, and return a reference to the newly mapped value. If `key` is movable, `key` is left in a (valid) unspecified state. == Synopsis Declared in `<bdlc_flathashmap.h>` [source,cpp,subs="verbatim,replacements,macros,-callouts"] ---- VALUE& operator[](xref:BloombergLP/bslmf/MovableRef.adoc[bslmf::MovableRef<KEY>] key); ---- [.small]#Created with https://www.mrdocs.com[MrDocs]#