tchars The set of token characters Synopsis Declared in header <boost/http_proto/rfc/token_rule.hpp> constexpr const urls::grammar::lut_chars tchars = "!#$%&'*+-.^_`|~" "0123456789" "ABCDEFGHIJKLMNOPQRSTUVWXYZ" "abcdefghijklmnopqrstuvwxyz"; Description BNF tchar = "!" / "#" / "$" / "%" / "&" / "'" / "*" / "+" / "-" / "." / "^" / "_" / "`" / "|" / "~" / DIGIT / ALPHA ; any VCHAR, except delimiters VCHAR = 0x21-0x7E Specification 3.2.3. Whitespace (rfc7230) B.1. Core Rules (rfc5234)