:relfileprefix: ../../
[#boost-urls-optional]

== xref:boost.adoc[pass:[boost]]::xref:boost/urls.adoc[pass:[urls]]::optional


The type of optional used by the library


=== Synopsis

Declared in header `<https://www.github.com/boostorg/url/blob/develop/include/boost/url/optional.hpp#L39[boost/url/optional.hpp,window=blank_]>`

[source,cpp,subs="verbatim,macros,-callouts"]
----
template<class T>
using optional = xref:boost.adoc[boost]::optional<T>;
----

=== Description

[WARNING]

This alias is no longer supported and
should not be used in new code. Please use
`boost::optional` instead.

This alias is included for backwards
compatibility with earlier versions of the
library.

However, it will be removed in future releases,
and using it in new code is not recommended.

Please use the updated version instead to
ensure compatibility with future versions of
the library.