[#boost-urls-url_view_base-empty]
= xref:boost.adoc[boost]::xref:boost/urls.adoc[urls]::xref:boost/urls/url_view_base.adoc[url_view_base]::empty
:relfileprefix: ../../../
:mrdocs:

Return true if the url is empty

== Synopsis

Declared in `<https://www.github.com/boostorg/url/blob/develop/include/boost/url/url_view_base.hpp#L221[boost/url/url_view_base.hpp]>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
bool
empty() const noexcept;
----

== Description

The empty string matches the _relative‐ref_ grammar.

== Example
[,cpp]
----
assert( url_view( "" ).empty() );
----
== Complexity
Constant.

== Exception Safety
Throws nothing.

== BNF
[,cpp]
----
relative-ref  = relative-part [ "?" query ] [ "#" fragment ]

relative-part = "//" authority path-abempty
              / path-absolute
              / path-noscheme
              / path-empty
----
== Specification
* https://datatracker.ietf.org/doc/html/rfc3986#section-4.2[]

== Return Value

`true` if the url is empty.


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