[#bsl-unordered_map-02b-operator_subs-0de] = xref:bsl.adoc[bsl]::xref:bsl/unordered_map-02b.adoc[unordered_map]::operator[] :relfileprefix: ../../ :mrdocs: Return a reference providing modifiable access to the mapped‐value associated with the specified `key` in this unordered map; if this unordered map does not already contain a `value_type` object with `key`, first insert a new `value_type` object having `key` and a default‐constructed `VALUE` object. Note that this method requires that the (template parameter) type `KEY` is `copy‐constructible` and the (template parameter) `VALUE` is "default‐constructible" (see {Requirements on `value_type`}). == Synopsis Declared in `<bslstl_unorderedmap.h>` [source,cpp,subs="verbatim,replacements,macros,-callouts"] ---- add_lvalue_reference<VALUE>::type operator[](xref:bsl/unordered_map-02b/key_type.adoc[key_type] const& key); ---- [.small]#Created with https://www.mrdocs.com[MrDocs]#