:relfileprefix: ../../../../
[#boost-urls-grammar-see_below-is_rule-0c]

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



=== Synopsis

Declared in header `<https://www.github.com/boostorg/url/blob/develop/include/boost/url/grammar/type_traits.hpp#L24[boost/url/grammar/type_traits.hpp,window=blank_]>`

[source,cpp,subs="verbatim,macros,-callouts"]
----
template<
    class T,
    class = void>
struct is_rule
    : std::false_type;
----