:relfileprefix: ../../../
[#boost-urls-grammar-ref-03]

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



== Synopsis

Declared in header `<https://www.github.com/boostorg/url/blob/develop/include/boost/url/grammar/parse.hpp#L113[boost/url/grammar/parse.hpp,window=blank_]>`

[source,cpp,subs="verbatim,macros,-callouts"]
----
template<class Rule>
constexpr
detail::rule_ref<Rule>
ref(Rule const& r) noexcept;
----