:relfileprefix: ../../../
[#boost-urls-segments_encoded_ref-insert-0d]

= xref:boost.adoc[pass:[boost]]::xref:boost/urls.adoc[pass:[urls]]::xref:boost/urls/segments_encoded_ref.adoc[pass:[segments_encoded_ref]]::insert


Insert segments


== Synopsis

Declared in header `<https://www.github.com/boostorg/url/blob/develop/include/boost/url/segments_encoded_ref.hpp#L453[boost/url/segments_encoded_ref.hpp,window=blank_]>`

[source,cpp,subs="verbatim,macros,-callouts"]
----
xref:boost/urls/segments_encoded_base/iterator.adoc[iterator]
insert(
    xref:boost/urls/segments_encoded_base/iterator.adoc[iterator] before,
    xref:std.adoc[std]::initializer_list<xref:boost/urls/pct_string_view.adoc[pct_string_view]> init);
----

== Description


This function inserts the segments
in an initializer list before the
specified position.
Reserved characters in the list are
automatically escaped.
Escapes in the list are preserved.



All iterators that are equal to
`before` or come after are invalidated.
[NOTE]

None of the character buffers referenced
by the list may overlap the character
buffer of the underlying url, or else
the behavior is undefined.

=== Example
[,cpp]
----
url u( "/file.txt" );

u.encoded_segments().insert( u.encoded_segments().begin(), { "path", "to" } );
----

=== Complexity

Linear in `init.size() + this-&gt;url().encoded_resource().size()`.

=== Exception Safety

Strong guarantee.
Calls to allocate may throw.
Exceptions thrown on invalid input.



== Exceptions

|===
| Name | Thrown on

| `system_error`
| 
The list contains an invalid percent-encoding.

|===


== Return Value


An iterator to the first
element inserted, or `before` if
`init.size() &equals;&equals; 0`.



== Parameters

|===
| Name | Description 

| *before*
| 
An iterator before which
the list is inserted. This may
be equal to `end()`.

| *init*
| 
The list of segments to insert.

|===