:relfileprefix: ../../../../
[#boost-urls-grammar-lut_chars-2constructor-074]

== xref:boost.adoc[pass:[boost]]::xref:boost/urls.adoc[pass:[urls]]::xref:boost/urls/grammar.adoc[pass:[grammar]]::xref:boost/urls/grammar/lut_chars.adoc[pass:[lut_chars]]::lut_chars


Constructor


=== Synopsis

Declared in header `<https://www.github.com/boostorg/url/blob/develop/include/boost/url/grammar/lut_chars.hpp#L188[boost/url/grammar/lut_chars.hpp,window=blank_]>`

[source,cpp,subs="verbatim,macros,-callouts"]
----
constexpr
lut_chars(char const* s) noexcept;
----

=== Description


This function constructs a character
set which has as members, all of the
characters present in the null-terminated
string `s`.
[,cpp]
----
constexpr lut_chars digits = "0123456789";
----

=== Linear in `::strlen(s)`, or constant

if `s` is a constant expression.

=== Throws nothing.





=== Parameters

|===
| Name | Description 

| *s*
| 
A null-terminated string.

|===