[#BloombergLP-bslstl-Function_InvokerUtilNullCheck-09]
= xref:BloombergLP.adoc[BloombergLP]::xref:BloombergLP/bslstl.adoc[bslstl]::xref:BloombergLP/bslstl/Function_InvokerUtilNullCheck-03.adoc[Function&lowbar;InvokerUtilNullCheck]&lt;xref:bsl/function-0a.adoc[bsl::function&lt;PROTO&gt;]&gt;
:relfileprefix: ../../
:mrdocs:

Specialization of null checker for instantiations of `bsl&colon;&colon;function`&period; This specialization treats an empty `bsl&colon;&colon;function` as a null object&period;

== Synopsis

Declared in `&lt;bslstl&lowbar;function&period;h&gt;`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
template&lt;class PROTO&gt;
struct xref:BloombergLP/bslstl/Function_InvokerUtilNullCheck-03.adoc[Function&lowbar;InvokerUtilNullCheck]&lt;xref:bsl/function-0a.adoc[bsl::function&lt;PROTO&gt;]&gt;;
----

== Static Member Functions

[cols="1,4"]
|===
| Name| Description
| xref:BloombergLP/bslstl/Function_InvokerUtilNullCheck-09/isNull.adoc[`isNull`] 
| Return true if the `bsl&colon;&colon;function` specified by `f` is empty&semi; else false&period;
|===



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