:relfileprefix: ../../../../ [#boost-urls-grammar-lut_chars-operator_call-0fe] == xref:boost.adoc[pass:[boost]]::xref:boost/urls.adoc[pass:[urls]]::xref:boost/urls/grammar.adoc[pass:[grammar]]::xref:boost/urls/grammar/lut_chars.adoc[pass:[lut_chars]]::operator() Return true if ch is in the character set. === Synopsis Declared in header `` [source,cpp,subs="verbatim,macros,-callouts"] ---- constexpr bool operator()(unsigned char ch) const noexcept; ---- === Description This function returns true if the character `ch` is in the set, otherwise it returns false. === Constant. === Throws nothing. === Parameters |=== | Name | Description | *ch* | The character to test. |===