The set of letters and digits.

Synopsis

Defined in header <boost/url/grammar/alnum_chars.hpp>

constexpr implementation-defined alnum_chars;

Example

Character sets are used with rules and the functions find_if and find_if_not.

result< string_view > = parse( "Johnny42", token_rule( alnumchars ) );

BNF

ALNUM       = ALPHA / DIGIT

ALPHA       = %x41-5A / %x61-7A
            ; A-Z / a-z

DIGIT       = %x30-39
            ; 0-9

Specification

See Also

find_if, find_if_not, parse, token_rule.

Convenience header <boost/url/grammar.hpp>