asSlice(*&slice)
	isSlice(*&slice)

	asString(str)
	isString(str)
	asString(str + "a")
	isString(str + "a")
	asString("a" + str)
	isString("a" + str)
	asString(str + str)
	isString(str + str)
	str += "a"
	str += str
	asString(String('a'))
	isString(String('a'))
	asString(String([]byte(slice)))
	isString(String([]byte(slice)))
	asString(String([]byte(nil)))
	isString(String([]byte(nil)))

	IsInteger
	IsUnsigned
	IsFloat
	IsComplex
	IsString
	IsUntyped

	IsOrdered   = IsInteger | IsFloat | IsString
	IsNumeric   = IsInteger | IsFloat | IsComplex
	IsConstType = IsBoolean | IsNumeric | IsString
)

// A Basic represents a basic type.
type Basic struct {
	kind BasicKind
	info BasicInfo
	name string
}

// Kind returns the kind of basic type b.

	IsInteger
	IsUnsigned
	IsFloat
	IsComplex
	IsString
	IsUntyped

	IsOrdered   = IsInteger | IsFloat | IsString
	IsNumeric   = IsInteger | IsFloat | IsComplex
	IsConstType = IsBoolean | IsNumeric | IsString
)

// A Basic represents a basic type.
type Basic struct {
	kind BasicKind
	info BasicInfo
	name string
}

// Kind returns the kind of basic type b.

	if slist == nil {
		return ""
	}
	var r string
	if slist.isatom {
		if slist.isstring {
			r = slist.String()
		} else {
			r = fmt.Sprintf("%v", slist.Integer())
		}
	} else {
		if doparen {
			r += "("
		}
		r += slist.Car().PrintOne(true)
		if slist.Cdr() != nil {
			r += " "
			r += slist.Cdr().PrintOne(false)
		}
		if doparen {
			r += ")"

	if isComplex(Vu) && isComplex(Tu) {
		return true
	}

	// "V is an integer or a slice of bytes or runes and T is a string type"
	if (isInteger(Vu) || isBytesOrRunes(Vu)) && isString(Tu) {
		return true
	}

	// "V is a string and T is a slice of bytes or runes"
	if isString(Vu) && isBytesOrRunes(Tu) {
		return true
	}

	// package unsafe:

(ArraySelect [i] x:(Load <t> ptr mem)) =>
  @x.Block (Load <v.Type> (OffPtr <v.Type.PtrTo()> [t.Elem().Size()*i] ptr) mem)

(StringPtr x:(Load <t> ptr mem)) && t.IsString() => @x.Block (Load <typ.BytePtr> ptr mem)
(StringLen x:(Load <t> ptr mem)) && t.IsString() => @x.Block (Load <typ.Int>
      (OffPtr <typ.IntPtr> [config.PtrSize] ptr)
      mem)

// NOTE removed must-not-be-SSA condition.

	scope.Debugf("validatePortNumberString %v:", val)
	if !util.IsString(val) {
		return util.NewErrs(fmt.Errorf("validatePortNumberString(%s) bad type %T, want string", path, val))
	}
	if val.(string) == "*" || val.(string) == "" {
		return nil
	}
	intV, err := strconv.ParseInt(val.(string), 10, 32)
	if err != nil {
		return util.NewErrs(fmt.Errorf("%s : %s", path, err))
	}
	return validatePortNumber(path, intV)
}

	case int64:
		return v, nil
	case int:
		return int64(v), nil
	case string:
		i, err := strconv.Atoi(v)
		return int64(i), err
	default:
		return 0, errors.New("Invalid number format")
	}
}

// isString - Safely check if val is of type string without causing panic.
func isString(val interface{}) bool {
	_, ok := val.(string)
	return ok
}

// ContentLengthRange - policy content-length-range field.

	if isComplex(Vu) && isComplex(Tu) {
		return true
	}

	// "V is an integer or a slice of bytes or runes and T is a string type"
	if (isInteger(Vu) || isBytesOrRunes(Vu)) && isString(Tu) {
		return true
	}

	// "V is a string and T is a slice of bytes or runes"
	if isString(Vu) && isBytesOrRunes(Tu) {
		return true
	}

	// package unsafe:

// If explicit is true, then conversions from integer to string are
// also allowed.
func ConvertVal(v constant.Value, t *types.Type, explicit bool) constant.Value {
	switch ct := v.Kind(); ct {
	case constant.Bool:
		if t.IsBoolean() {
			return v
		}

	case constant.String:
		if t.IsString() {
			return v
		}

	case constant.Int:
		if explicit && t.IsString() {
			return tostr(v)
		}
		fallthrough