}
	var hb, lb byte
	if hb, err = fromHex(v[0]); err != nil {
		return 0, err
	}
	if lb, err = fromHex(v[1]); err != nil {
		return 0, err
	}
	return hb<<4 | lb, nil
}

func isQPDiscardWhitespace(r rune) bool {
	switch r {
	case '\n', '\r', ' ', '\t':
		return true
	}
	return false
}

var (
	crlf       = []byte("\r\n")
	lf         = []byte("\n")
	softSuffix = []byte("=")
)