[#boost-urls-params_encoded_ref-unset]
= xref:boost.adoc[boost]::xref:boost/urls.adoc[urls]::xref:boost/urls/params_encoded_ref.adoc[params_encoded_ref]::unset
:relfileprefix: ../../../
:mrdocs:


Remove the value on an element

== Synopsis


Declared in `<https://www.github.com/boostorg/url/blob/develop/include/boost/url/params_encoded_ref.hpp#L832[boost/url/params_encoded_ref.hpp]>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
xref:boost/urls/params_encoded_base/iterator.adoc[iterator]
unset(xref:boost/urls/params_encoded_base/iterator.adoc[iterator] pos) noexcept;
----

== Description


This function removes the value of        an element at the specified position.        After the call returns, `has_value`        for the element is false.

All iterators that are equal to        `pos` or come after are invalidated.


=== Example

[,cpp]
----
url u( "?first=John&last=Doe" );

u.encoded_params().unset( u.encoded_params().begin() );

assert( u.encoded_query() == "first&last=Doe" );
----

=== Complexity

Linear in `this‐>url().encoded_query().size()`.


=== Exception Safety

Throws nothing.



== Return Value


An iterator to the element.



== Parameters


|===
| Name | Description

| *pos*
| An iterator to the element.


|===



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