[#boost-urls-url-2constructor-002]
= xref:boost.adoc[boost]::xref:boost/urls.adoc[urls]::xref:boost/urls/url.adoc[url]::url
:relfileprefix: ../../../
:mrdocs:


Constructor

== Synopsis


Declared in `<https://www.github.com/boostorg/url/blob/develop/include/boost/url/url.hpp#L169[boost/url/url.hpp]>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
explicit
url(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.        The new url retains ownership by        allocating a copy of the passed string.


=== Example

[,cpp]
----
url u( "https://www.example.com" );
----

=== Effects

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

=== Postconditions

[,cpp]
----
this->buffer().data() != s.data()
----

=== Complexity

Linear in `s.size()`.


=== Exception Safety

Calls to allocate may throw.        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]

Constructor

This function constructs a URL from        the string `s`, which must contain a        valid _URI_ or _relative‐ref_        or else an exception is thrown.        The new url retains ownership by        allocating a copy of the passed string.


=== Example

[,cpp]
----
url u( "https://www.example.com" );
----

=== Effects

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

=== Postconditions

[,cpp]
----
this->buffer().data() != s.data()
----

=== Complexity

Linear in `s.size()`.


=== Exception Safety

Calls to allocate may throw.        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 does not contain a valid url.


| `system_error`
| The input does not contain a valid url.


|===

== Parameters


|===
| Name | Description

| *s*
| The string to parse.


| *s*
| The string to parse.


|===



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