:relfileprefix: ../../../
[#44F13B9E5D27CC7979D0DC5E2965651E58F41047]

= Function operator+

pass:v,q[Return the union of two character sets.]


== Synopsis

Declared in header `</boost/url/grammar/lut_chars.hpp#L291[boost/url/grammar/lut_chars.hpp,window=blank_]>`

[source,cpp,subs="verbatim,macros,-callouts"]
----
constexpr
xref:boost/urls/grammar/lut_chars.adoc[lut_chars]
operator+(
    const xref:boost/urls/grammar/lut_chars.adoc[lut_chars]& cs0,
    const xref:boost/urls/grammar/lut_chars.adoc[lut_chars]& cs1) noexcept;
----

== Description

pass:v,q[This function returns a new character] pass:v,q[set which contains all of the characters]
pass:v,q[in `cs0` as well as all of the characters]
pass:v,q[in `cs`.]

=== Example
pass:v,q[This creates a character set which]
pass:v,q[includes all letters and numbers]
[,cpp]
----
constexpr lut_chars alpha_chars(
    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    "abcdefghijklmnopqrstuvwxyz");

constexpr lut_chars alnum_chars = alpha_chars + "0123456789";
----

=== Complexity
pass:v,q[Constant.]



== Return Value

* `lut_chars` 


== Parameters

|===
| Name | Type 

| *cs0*
| ``

| *cs1*
| ``

|===



