:relfileprefix: ../../../
[#586DA1BD75E17D2E9D967C96F546373E4502BE04]

= Function params_ref::insert

pass:v,q[Insert elements]


== Synopsis

Declared in header `</boost/url/params_ref.hpp#L558[boost/url/params_ref.hpp,window=blank_]>`

[source,cpp,subs="verbatim,macros,-callouts"]
----
template<class FwdIt>
xref:boost/urls/params_base.adoc[params_base]::xref:boost/urls/params_base/iterator.adoc[iterator]
insert(
    xref:boost/urls/params_base.adoc[params_base]::xref:boost/urls/params_base/iterator.adoc[iterator] before,
    FwdIt first,
    FwdIt last);
----

== Description

pass:v,q[This function inserts a range of] pass:v,q[params before the specified position.]
pass:v,q[All iterators that are equal to]
pass:v,q[`before` or come after are invalidated.]
[NOTE]
pass:v,q[The strings referenced by the inputs]
pass:v,q[must not come from the underlying url,]
pass:v,q[or else the behavior is undefined.]

=== Mandates
[,cpp]
----
std::is_convertible< std::iterator_traits< FwdIt >::reference_type, param_view >::value == true
----

=== Complexity
pass:v,q[Linear in `this->url().encoded_query().size()`.]

=== Exception Safety
pass:v,q[Strong guarantee.]
pass:v,q[Calls to allocate may throw.]



== Return Value

* `iterator` 


== Parameters

|===
| Name | Type 

| *before*
| `iterator`

| *first*
| `FwdIt`

| *last*
| `FwdIt`

|===