[#boost-urls-grammar-operator_minus]
= xref:boost.adoc[boost]::xref:boost/urls.adoc[urls]::xref:boost/urls/grammar.adoc[grammar]::operator‐
:relfileprefix: ../../../
:mrdocs:


Return a new character set by subtracting

== Synopsis


Declared in `<https://www.github.com/boostorg/url/blob/develop/include/boost/url/grammar/lut_chars.hpp#L336[boost/url/grammar/lut_chars.hpp]>`

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

== Description


This function returns a new character        set which is formed from all of the        characters in `cs0` which are not in `cs`.


=== Example

This statement declares a character set        containing all the lowercase letters        which are not vowels:

[,cpp]
----
constexpr lut_chars consonants = lut_chars("abcdefghijklmnopqrstuvwxyz") - "aeiou";
----

=== Complexity

Constant.



== Return Value


The new character set.



== Parameters


|===
| Name | Description

| *cs0*
| A character set to join.


| *cs1*
| A character set to join.


|===



[.small]#Created with https://www.mrdocs.com[MrDocs]#