:relfileprefix: ../../../
[#boost-urls-url_view-2constructor-025]

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


Constructor


== Synopsis

Declared in header `<https://www.github.com/boostorg/url/blob/develop/include/boost/url/url_view.hpp#L197[boost/url/url_view.hpp,window=blank_]>`

[source,cpp,subs="verbatim,macros,-callouts"]
----
url_view(core::string_view s);
----

== Description


This function constructs a URL from
the string `s`, which must contain a
valid
_URI_
or
_relative-ref_
or else an exception is thrown. Upon
successful construction, the view
refers to the characters in the
buffer pointed to by `s`.
Ownership is not transferred; The caller
is responsible for ensuring that the
lifetime of the buffer extends until
it is no longer referenced.

=== Example
[,cpp]
----
url_view u( "http://www.example.com/index.htm" );
----

=== Effects
[,cpp]
----
return parse_uri_reference( s ).value();
----

=== Complexity

Linear in `s.size()`.

=== Exception Safety

Exceptions thrown on invalid input.

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

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

=== Specification

* link:https://datatracker.ietf.org/doc/html/rfc3986#section-4.1[4.1. URI Reference]



== Exceptions

|===
| Name | Thrown on

| `system_error`
| 
The input failed to parse correctly.

|===



== Parameters

|===
| Name | Description 

| *s*
| 
The string to parse.

|===




== See Also


xref:boost/urls/parse_uri_reference.adoc[parse_uri_reference]
.