[#BloombergLP-ball-UserFields-2constructor-09] = xref:BloombergLP.adoc[BloombergLP]::xref:BloombergLP/ball.adoc[ball]::xref:BloombergLP/ball/UserFields.adoc[UserFields]::UserFields :relfileprefix: ../../../ :mrdocs: Create an empty `UserFields` object. Optionally specify a `basicAllocator` used to supply memory. If `basicAllocator` is 0, the currently installed default allocator is used. == Synopsis Declared in `<ball_userfields.h>` [source,cpp,subs="verbatim,replacements,macros,-callouts"] ---- explicit UserFields(xref:BloombergLP/bslma/Allocator.adoc[bslma::Allocator]* basicAllocator = 0); ---- [.small]#Created with https://www.mrdocs.com[MrDocs]#