[#boost-urls-param_pct_view-2constructor-03]
= xref:boost.adoc[boost]::xref:boost/urls.adoc[urls]::xref:boost/urls/param_pct_view.adoc[param&lowbar;pct&lowbar;view]::param&lowbar;pct&lowbar;view
:relfileprefix: ../../../
:mrdocs:

Construction

== Synopsis

Declared in `&lt;https://www.github.com/boostorg/url/blob/develop/include/boost/url/param.hpp#L851[boost&sol;url&sol;param&period;hpp]&gt;`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
explicit
param&lowbar;pct&lowbar;view(xref:boost/urls/param_view.adoc[param&lowbar;view] const& p);
----

== Description

This converts a param which may contain unvalidated percent&hyphen;escapes into a param whose key and value are guaranteed to contain strings with no invalid percent&hyphen;escapes, otherwise an exception is thrown&period;

The new key and value reference the same corresponding underlying character buffers&period; Ownership of the buffers is not transferred&semi; the caller is responsible for ensuring that the assigned buffers remain valid until they are no longer referenced&period;

== Example
[,cpp]
----
param_pct_view qp( param_view( "key", "value" ) );
----
== Complexity
Linear in `key&period;size() &plus; value&period;size()`&period;

== Exception Safety
Exceptions thrown on invalid input&period;

== Exceptions

[cols=2]
|===
| Name
| Thrown on
| `system&lowbar;error`
| `key` or `value` contains an invalid percent escape&period;
|===

== Parameters

[cols=2]
|===
| Name
| Description
| *p*
| The param to construct from&period;
|===


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