:relfileprefix: ../../../
[#3752AFA9A07EF9973B2A7F335BB5C0B4A5CBA871]

= Function ref



== Synopsis

Declared in header `</boost/url/grammar/parse.hpp#L113[boost/url/grammar/parse.hpp,window=blank_]>`

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