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[#8B0487D9FBD591BF3D4E4663ECA58B192C9CE2C0]

= Function url_view_base::has_scheme

pass:v,q[Return true a scheme is present]


== Synopsis

Declared in header `</boost/url/url_view_base.hpp#L339[boost/url/url_view_base.hpp,window=blank_]>`

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

== Description

pass:v,q[This function returns true if this] pass:v,q[contains a scheme.]

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

=== Complexity
pass:v,q[Constant.]

=== Exception Safety
pass:v,q[Throws nothing.]

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

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

scheme          = ALPHA *( ALPHA / DIGIT / "+" / "-" / "." )
----

=== Specification

* link:https://datatracker.ietf.org/doc/html/rfc3986#section-3.1[3.1. Scheme (rfc3986)]



== Return Value

* `bool`