assert(!isTypeParam(T))
		return s.WordSize
	case *Basic:
		// Strings are like slices and interfaces.
		if t.Info()&IsString != 0 {
			return s.WordSize
		}
	case *TypeParam, *Union:
		panic("unreachable")
	}
	a := s.Sizeof(T) // may be 0 or negative
	// spec: "For a variable x of any type: unsafe.Alignof(x) is at least 1."
	if a < 1 {
		return 1
	}

		name += " (" + strings.Join(parentheticals, ", ") + ")"
	}

	return name
}

func typeName(t types.Type) string {
	type hasTypeName interface{ Obj() *types.TypeName } // Alias, Named, TypeParam
	switch t := t.(type) {
	case *types.Basic:
		return t.Name()
	case hasTypeName:
		return t.Obj().Name()
	}
	return ""
}

func run(pass *analysis.Pass) (interface{}, error) {

func (a *Alias) String() string { return TypeString(a, nil) }

// Underlying returns the [underlying type] of the alias type a, which is the
// underlying type of the aliased type. Underlying types are never Named,
// TypeParam, or Alias types.
//
// [underlying type]: https://go.dev/ref/spec#Underlying_types.
func (a *Alias) Underlying() Type { return unalias(a).Underlying() }

// Origin returns the generic Alias type of which a is an instance.

	origT := T
	V := Unalias(x.typ)
	T = Unalias(T)

	// x's type is identical to T
	if Identical(V, T) {
		return true, 0
	}

	Vu := under(V)
	Tu := under(T)
	Vp, _ := V.(*TypeParam)
	Tp, _ := T.(*TypeParam)

	// x is an untyped value representable by a value of type T.
	if isUntyped(Vu) {
		assert(Vp == nil)
		if Tp != nil {
			// T is a type parameter: x is assignable to T if it is

	opTypeParam  = 'T' // .TypeParams.At(i) (Named, Signature)
	opConstraint = 'C' // .Constraint()     (TypeParam)

	// type->object operators
	opAt     = 'A' // .At(i)		 (Tuple)
	opField  = 'F' // .Field(i)	 (Struct)
	opMethod = 'M' // .Method(i) (Named or Interface; not Struct: "promoted" names are ignored)
	opObj    = 'O' // .Obj()		 (Named, TypeParam)
)

// For is equivalent to new(Encoder).For(obj).
//

	if ok, _ := x.assignableTo(check, T, cause); ok {
		return true
	}

	origT := T
	V := Unalias(x.typ)
	T = Unalias(T)
	Vu := under(V)
	Tu := under(T)
	Vp, _ := V.(*TypeParam)
	Tp, _ := T.(*TypeParam)

	// "V and T have identical underlying types if tags are ignored
	// and V and T are not type parameters"
	if IdenticalIgnoreTags(Vu, Tu) && Vp == nil && Tp == nil {
		return true
	}

func (a *Alias) String() string { return TypeString(a, nil) }

// Underlying returns the [underlying type] of the alias type a, which is the
// underlying type of the aliased type. Underlying types are never Named,
// TypeParam, or Alias types.
//
// [underlying type]: https://go.dev/ref/spec#Underlying_types.
func (a *Alias) Underlying() Type { return unalias(a).Underlying() }

// Origin returns the generic Alias type of which a is an instance.

	if ok, _ := x.assignableTo(check, T, cause); ok {
		return true
	}

	origT := T
	V := Unalias(x.typ)
	T = Unalias(T)
	Vu := under(V)
	Tu := under(T)
	Vp, _ := V.(*TypeParam)
	Tp, _ := T.(*TypeParam)

	// "V and T have identical underlying types if tags are ignored
	// and V and T are not type parameters"
	if IdenticalIgnoreTags(Vu, Tu) && Vp == nil && Tp == nil {
		return true
	}

// so we could depend on it from other packages without
// introducing an import cycle.)
type Type interface {
	// Underlying returns the underlying type of a type.
	// Underlying types are never Named, TypeParam, or Alias types.
	//
	// See https://go.dev/ref/spec#Underlying_types.
	Underlying() Type

	// String returns a string representation of a type.
	String() string
}

	origT := T
	V := Unalias(x.typ)
	T = Unalias(T)

	// x's type is identical to T
	if Identical(V, T) {
		return true, 0
	}

	Vu := under(V)
	Tu := under(T)
	Vp, _ := V.(*TypeParam)
	Tp, _ := T.(*TypeParam)

	// x is an untyped value representable by a value of type T.
	if isUntyped(Vu) {
		assert(Vp == nil)
		if Tp != nil {
			// T is a type parameter: x is assignable to T if it is