Int64
	Uint
	Uint8
	Uint16
	Uint32
	Uint64
	Uintptr
	Float32
	Float64
	Complex64
	Complex128
	String
	UnsafePointer

	// types for untyped values
	UntypedBool
	UntypedInt
	UntypedRune
	UntypedFloat
	UntypedComplex
	UntypedString
	UntypedNil

	// aliases
	Byte = Uint8
	Rune = Int32
)

// BasicInfo is a set of flags describing properties of a basic type.
type BasicInfo int

	Int64
	Uint
	Uint8
	Uint16
	Uint32
	Uint64
	Uintptr
	Float32
	Float64
	Complex64
	Complex128
	String
	UnsafePointer

	// types for untyped values
	UntypedBool
	UntypedInt
	UntypedRune
	UntypedFloat
	UntypedComplex
	UntypedString
	UntypedNil

	// aliases
	Byte = Uint8
	Rune = Int32
)

// BasicInfo is a set of flags describing properties of a basic type.
type BasicInfo int

	UnsafePointer: {UnsafePointer, 0, "Pointer"},

	UntypedBool:    {UntypedBool, IsBoolean | IsUntyped, "untyped bool"},
	UntypedInt:     {UntypedInt, IsInteger | IsUntyped, "untyped int"},
	UntypedRune:    {UntypedRune, IsInteger | IsUntyped, "untyped rune"},
	UntypedFloat:   {UntypedFloat, IsFloat | IsUntyped, "untyped float"},
	UntypedComplex: {UntypedComplex, IsComplex | IsUntyped, "untyped complex"},

	UnsafePointer: {UnsafePointer, 0, "Pointer"},

	UntypedBool:    {UntypedBool, IsBoolean | IsUntyped, "untyped bool"},
	UntypedInt:     {UntypedInt, IsInteger | IsUntyped, "untyped int"},
	UntypedRune:    {UntypedRune, IsInteger | IsUntyped, "untyped rune"},
	UntypedFloat:   {UntypedFloat, IsFloat | IsUntyped, "untyped float"},
	UntypedComplex: {UntypedComplex, IsComplex | IsUntyped, "untyped complex"},

	types.Universe.Lookup("rune").Type(),

	// error
	types.Universe.Lookup("error").Type(),

	// untyped types
	types.Typ[types.UntypedBool],
	types.Typ[types.UntypedInt],
	types.Typ[types.UntypedRune],
	types.Typ[types.UntypedFloat],
	types.Typ[types.UntypedComplex],
	types.Typ[types.UntypedString],
	types.Typ[types.UntypedNil],

	// package unsafe
	types.Typ[types.UnsafePointer],

}

func mixUntyped(t1, t2 *types.Type) *types.Type {
	if t1 == t2 {
		return t1
	}

	rank := func(t *types.Type) int {
		switch t {
		case types.UntypedInt:
			return 0
		case types.UntypedRune:
			return 1
		case types.UntypedFloat:
			return 2
		case types.UntypedComplex:
			return 3
		}
		base.Fatalf("bad type %v", t)
		panic("unreachable")
	}

	if rank(t2) > rank(t1) {

		for _, vt := range vtypes {
			u, _ := vt.Underlying().(*types.Basic)
			if u != nil && u.Info()&types.IsInteger != 0 {
				switch u.Kind() {
				case types.Byte, types.Rune, types.UntypedRune:
					continue
				}
				V0 = vt
				break
			}
		}

		if V0 == nil {
			// No source types are non-byte or rune integer types.
			return
		}

	var kind BasicKind
	switch k {
	case token.INT:
		kind = UntypedInt
	case token.FLOAT:
		kind = UntypedFloat
	case token.IMAG:
		kind = UntypedComplex
	case token.CHAR:
		kind = UntypedRune
	case token.STRING:
		kind = UntypedString
	default:
		panic("unreachable")
	}

	val := makeFromLiteral(lit, k)
	if val.Kind() == constant.Unknown {
		x.mode = invalid
		x.typ = Typ[Invalid]

			return m.t&argComplex != 0

		case types.UntypedString,
			types.String:
			return m.t&argString != 0

		case types.UnsafePointer:
			return m.t&(argPointer|argInt) != 0

		case types.UntypedRune:
			return m.t&(argInt|argRune) != 0

		case types.UntypedNil:
			return false

		case types.Invalid:
			return true // Probably a type check problem.
		}
		panic("unreachable")
	}

	var kind BasicKind
	switch k {
	case syntax.IntLit:
		kind = UntypedInt
	case syntax.FloatLit:
		kind = UntypedFloat
	case syntax.ImagLit:
		kind = UntypedComplex
	case syntax.RuneLit:
		kind = UntypedRune
	case syntax.StringLit:
		kind = UntypedString
	default:
		panic("unreachable")
	}

	val := makeFromLiteral(lit, k)
	if val.Kind() == constant.Unknown {
		x.mode = invalid