The set of all letters

Synopsis

constexpr /* implementation-defined */ alpha_chars = alpha_chars{};

Example

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

system::result< core::string_view > rv = parse( "JohnDoe", token_rule( alpha_chars ) );

BNF

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

Specification

• B.1. Core Rules (rfc5234)

See Also

find_if, find_if_not, parse, token_rule.