:relfileprefix: ../../../ [#boost-urls-grammar-lut_chars] = xref:boost.adoc[pass:[boost]]::xref:boost/urls.adoc[pass:[urls]]::xref:boost/urls/grammar.adoc[pass:[grammar]]::lut_chars A set of characters == Synopsis Declared in header `` [source,cpp,subs="verbatim,macros,-callouts"] ---- class lut_chars; ---- == Member Functions [cols=2,separator=¦] |=== ¦Name ¦Description ¦xref:boost/urls/grammar/lut_chars/find_if.adoc[`find_if`] ¦ ¦xref:boost/urls/grammar/lut_chars/find_if_not.adoc[`find_if_not`] ¦ ¦xref:boost/urls/grammar/lut_chars/2constructor.adoc[`lut_chars`] [.small]#[constructor]# ¦ Constructor ¦xref:boost/urls/grammar/lut_chars/operator_call.adoc[`operator()`] ¦ Return true if ch is in the character set. ¦xref:boost/urls/grammar/lut_chars/operator_bitnot.adoc[`operator~`] ¦ Return a new character set which is the complement of another character set. |=== == Friends [cols=2,separator=¦] |=== ¦Name ¦Description ¦xref:boost/urls/grammar/lut_chars/08friend-02.adoc[`operator+`] ¦ Return the union of two character sets. ¦xref:boost/urls/grammar/lut_chars/08friend-07.adoc[`operator-`] ¦ Return a new character set by subtracting |=== == Description The characters defined by instances of this set are provided upon construction. The `constexpr` implementation allows these to become compile-time constants. === Example Character sets are used with rules and the functions xref:boost/urls/grammar/lut_chars/find_if.adoc[find_if] and xref:boost/urls/grammar/lut_chars/find_if_not.adoc[find_if_not] . [,cpp] ---- constexpr lut_chars vowel_chars = "AEIOU" "aeiou"; system::result< core::string_view > rv = parse( "Aiea", token_rule( vowel_chars ) ); ---- == See Also xref:boost/urls/grammar/lut_chars/find_if.adoc[find_if] , xref:boost/urls/grammar/lut_chars/find_if_not.adoc[find_if_not] , xref:boost/urls/grammar/parse-02.adoc[parse] , xref:boost/urls/grammar/token_rule.adoc[token_rule] .