:relfileprefix: ../../../
[#boost-urls-grammar-dec_octet_rule]

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


Match a decimal octet


=== Synopsis

Declared in header `<https://www.github.com/boostorg/url/blob/develop/include/boost/url/grammar/dec_octet_rule.hpp#L104[boost/url/grammar/dec_octet_rule.hpp,window=blank_]>`

[source,cpp,subs="verbatim,macros,-callouts"]
----
constexpr
pass:q[_implementation-defined_] dec_octet_rule = {};
----

=== Description


A decimal octet is precise way of
saying a number from 0 to 255. These
are commonly used in IPv4 addresses.
[,cpp]
----
using value_type = unsigned char;
----

=== Rules are used with the function

xref:boost/urls/grammar/parse-02.adoc[parse]
.
[,cpp]
----
system::result< unsigned char > rv = parse( "255", dec_octet_rule );
----
[,cpp]
----
dec-octet   = DIGIT                 ; 0-9
            / %x31-39 DIGIT         ; 10-99
            / "1" 2DIGIT            ; 100-199
            / "2" %x30-34 DIGIT     ; 200-249
            / "25" %x30-35          ; 250-255
----

* link:https://datatracker.ietf.org/doc/html/rfc3986#section-3.2.2[3.2.2.  Host (rfc3986)]



=== See Also


xref:boost/urls/grammar/parse-02.adoc[parse]
.