:relfileprefix: ../../
[#A120182657BCD0170BF37F010515FADE5721FF94]

= optional



== Synopsis

Declared in header `</boost/url/optional.hpp#L39[boost/url/optional.hpp,window=blank_]>`

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