[#boost-urls-grammar-alpha_chars]
= xref:boost.adoc[boost]::xref:boost/urls.adoc[urls]::xref:boost/urls/grammar.adoc[grammar]::alpha_chars
:relfileprefix: ../../../
:mrdocs:

The set of all letters

== Synopsis

Declared in `<https://www.github.com/boostorg/url/blob/develop/include/boost/url/grammar/alpha_chars.hpp#L81[boost/url/grammar/alpha_chars.hpp]>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
constexpr /* implementation-defined */ alpha_chars = alpha_chars{};
----

== Description

== Example
Character sets are used with rules and the functions xref:boost/urls/grammar/find_if.adoc[`find_if`] and xref:boost/urls/grammar/find_if_not.adoc[`find_if_not`].

[,cpp]
----
system::result< core::string_view > rv = parse( "JohnDoe", token_rule( alpha_chars ) );
----
== BNF
[,cpp]
----
ALPHA       = %x41-5A / %x61-7A
            ; A-Z / a-z
----
== Specification
* https://datatracker.ietf.org/doc/html/rfc5234#appendix-B.1[]

== See Also

xref:boost/urls/grammar/find_if.adoc[`find&lowbar;if`], xref:boost/urls/grammar/find_if_not.adoc[`find&lowbar;if&lowbar;not`], xref:boost/urls/grammar/parse-09.adoc[`parse`], xref:boost/urls/grammar/token_rule.adoc[`token&lowbar;rule`]&period;


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