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


Match a series of rules in order

== Synopsis


Declared in `<https://www.github.com/boostorg/url/blob/develop/include/boost/url/grammar/tuple_rule.hpp#L122[boost/url/grammar/tuple_rule.hpp]>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
template<
    xref:boost/urls/grammar/Rule.adoc[Rule] R0,
    xref:boost/urls/grammar/Rule.adoc[Rule]... Rn>
constexpr
/* implementation-defined */::xref:boost/urls/grammar/implementation_defined/tuple_rule_t.adoc[tuple_rule_t]<R0, Rn...>
tuple_rule(
    R0 const& r0,
    Rn const&... rn) noexcept;
----

== Description


This matches a series of rules in the    order specified. Upon success the input    is adjusted to point to the first    unconsumed character. There is no    implicit specification of linear white    space between each rule.


=== Value Type

[,cpp]
----
using value_type = __see_below__;
----
The sequence rule usually returns a    `std::tuple` containing the the `value_type`    of each corresponding rule in the sequence,    except that `void` values are removed.    However, if there is exactly one non‐void    value type `T`, then the sequence rule    returns `system::result<T>` instead of    `system::result<tuple<...>>`.


=== Example

Rules are used with the function xref:boost/urls/grammar/parse-02.adoc[parse].

[,cpp]
----
system::result< std::tuple< unsigned char, unsigned char, unsigned char, unsigned char > > rv =
    parse( "192.168.0.1",
        tuple_rule(
            dec_octet_rule,
            squelch( delim_rule('.') ),
            dec_octet_rule,
            squelch( delim_rule('.') ),
            dec_octet_rule,
            squelch( delim_rule('.') ),
            dec_octet_rule ) );
----

=== BNF

[,cpp]
----
sequence     = rule1 rule2 rule3...
----

=== Specification

* link:https://datatracker.ietf.org/doc/html/rfc5234#section-3.1[3&period;1&period;  Concatenation (rfc5234)]



== Parameters


|===
| Name | Description

| *rn*
| A list of one or more rules to match


|===

== See Also


xref:boost/urls/grammar/dec_octet_rule.adoc[dec&lowbar;octet&lowbar;rule],        xref:boost/urls/grammar/delim_rule-01.adoc[delim&lowbar;rule],        xref:boost/urls/grammar/parse-02.adoc[parse],        xref:boost/urls/grammar/squelch.adoc[squelch]&period;






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