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

Return true a scheme is present

== Synopsis

Declared in `<https://www.github.com/boostorg/url/blob/develop/include/boost/url/url_view_base.hpp#L367[boost/url/url_view_base.hpp]>`

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

== Description

This function returns true if this contains a scheme.

== Example
[,cpp]
----
assert( url_view( "http://www.example.com" ).has_scheme() );
----
== Complexity
Constant.

== Exception Safety
Throws nothing.

== BNF
[,cpp]
----
URI             = scheme ":" hier-part [ "?" query ] [ "#" fragment ]

absolute-URI    = scheme ":" hier-part [ "?" query ]

scheme          = ALPHA *( ALPHA / DIGIT / "+" / "-" / "." )
----
== Specification
* https://datatracker.ietf.org/doc/html/rfc3986#section-3.1[]

== Return Value

`true` if the url contains a scheme.

== See Also

xref:boost/urls/url_view_base/scheme.adoc[`scheme`], xref:boost/urls/url_view_base/scheme_id.adoc[`scheme_id`].


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