assert(u01 == u00+1, "u01")
	assert(u02 == u03, "u02")
	assert(u03 == (1<<8)-1, "u03 size")

	// uint16
	var u10 uint16 = 0
	var u11 uint16 = 1
	var u12 uint16 = 65535
	var u13 uint16 = +65535
	assert(u11 == u10+1, "u11")
	assert(u12 == u13, "u12")

	// uint32
	var u20 uint32 = 0
	var u21 uint32 = 1
	var u22 uint32 = 4294967295
	var u23 uint32 = +4294967295
	assert(u21 == u20+1, "u21")

	u0 = uint(1)
	u1 uint = u0
	u2 = +1
	u3 = +u0
	u4 uint = +1
	u5 uint = +u4
	u6 = -1
	u7 = -u0
	u8 uint = - /* ERROR "overflows" */ 1
	u9 uint = -u4
	u10 = !u0 /* ERROR "not defined" */
	u11 = ^1
	u12 = ^i0
	u13 uint = ^ /* ERROR "overflows" */ 1
	u14 uint = ^u4
	u15 = *u0 /* ERROR "cannot indirect" */
	u16 = &u0
	u17 = *u16
	u18 = <-u16 /* ERROR "cannot receive" */
	u19 = ^uint(0)

		s.step = stateInStringEscU12
		return scanContinue
	}
	// numbers
	return s.error(c, "in \\u hexadecimal character escape")
}

// stateInStringEscU12 is the state after reading `"\u12` during a quoted string.
func stateInStringEscU12(s *scanner, c byte) int {
	if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' {
		s.step = stateInStringEscU123
		return scanContinue
	}