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

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

  


Constructor



=== Synopsis
  

[source,cpp,subs="verbatim,macros,-callouts"]
----
constexpr
xref:boost/urls/param/2constructor-09.adoc[pass:[param]]() = default;
----

[source,cpp,subs="verbatim,macros,-callouts"]
----
xref:boost/urls/param/2constructor-07.adoc[pass:[param]](xref:boost/urls/param.adoc[param]&& other) noexcept;
----

[source,cpp,subs="verbatim,macros,-callouts"]
----
constexpr
xref:boost/urls/param/2constructor-0d.adoc[pass:[param]](xref:boost/urls/param.adoc[param] const& other) = default;
----

[source,cpp,subs="verbatim,macros,-callouts"]
----
template<class OptionalString>
xref:boost/urls/param/2constructor-0b.adoc[pass:[param]](
    core::string_view key,
    OptionalString const& value);
----

[source,cpp,subs="verbatim,macros,-callouts"]
----
xref:boost/urls/param/2constructor-0a.adoc[pass:[param]](
    core::string_view key,
    core::string_view value,
    bool has_value) noexcept;
----
  
=== Description


Default constructed query parameters
have an empty key and no value.
[,cpp]
----
param qp;
----
[,cpp]
----
this->key == "" && this->value == "" && this->has_value == false
----

=== Constant.

=== Throws nothing.




=== Parameters

|===
| Name | Description 

| *key,*
| 
value The key and value to set.

|===