:relfileprefix: ../../../../
[#boost-urls-grammar-see_below-is_charset-0d]

== 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_charset



=== Synopsis

Declared in header `<https://www.github.com/boostorg/url/blob/develop/include/boost/url/grammar/charset.hpp#L30[boost/url/grammar/charset.hpp,window=blank_]>`

[source,cpp,subs="verbatim,macros,-callouts"]
----
template<class T>
struct xref:boost/urls/grammar/see_below/is_charset-0b.adoc[pass:[is_charset]]<T, void_t<decltype(std::declval<bool&>() =
                std::declval<T const&>().operator()(
                    std::declval<char>()))>>
    : std::true_type;
----