[#bsl-vectorBase-0aa9-data-0b] = xref:bsl.adoc[bsl]::xref:bsl/vectorBase-0aa9.adoc[vectorBase<unsigned long long>]::data :relfileprefix: ../../ :mrdocs: Return the address of the non‐modifiable first element in this vector, or a valid, but non‐dereferenceable pointer value if this vector is empty. == Synopsis Declared in `<bslstl_vector.h>` [source,cpp,subs="verbatim,replacements,macros,-callouts"] ---- unsigned long long const* data() const noexcept; ---- [.small]#Created with https://www.mrdocs.com[MrDocs]#