[#std-hash-05b-operator_call]
= xref:std.adoc[std]::xref:std/hash-05b.adoc[hash<folly::enable_std_hash_helper<folly::Optional<T>, remove_const_t<T>>>]::operator()
:relfileprefix: ../../
:mrdocs:

Computes the hash of an Optional.

== Synopsis

Declared in `<folly/Optional.h>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
size_t
operator()(xref:folly/Optional.adoc[folly::Optional<T>] const& obj) const;
----

== Return Value

The hash of the contained value, or 0 if empty.

== Parameters

[cols="1,4"]
|===
| Name| Description
| *obj*
| The Optional to hash.
|===


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