case 1:
		return typecheck.LookupRuntime(name, t.Elem())
	case 2:
		return typecheck.LookupRuntime(name, t.Elem(), t.Elem())
	}
	base.Fatalf("chanfn %d", n)
	return nil
}

func mapfn(name string, t *types.Type, isfat bool) ir.Node {
	if !t.IsMap() {
		base.Fatalf("mapfn %v", t)
	}
	if mapfast(t) == mapslow || isfat {
		return typecheck.LookupRuntime(name, t.Key(), t.Elem(), t.Key(), t.Elem())
	}

	// Note that this uses / always, even on Windows, because Go import
	// paths always use forward slashes.
	path := obj.imported.path
	elem := path
	if i := strings.LastIndex(elem, "/"); i >= 0 {
		elem = elem[i+1:]
	}
	if obj.name == "" || obj.name == "." || obj.name == elem {
		check.softErrorf(obj, UnusedImport, "%q imported and not used", path)
	} else {

	// Note that this uses / always, even on Windows, because Go import
	// paths always use forward slashes.
	path := obj.imported.path
	elem := path
	if i := strings.LastIndex(elem, "/"); i >= 0 {
		elem = elem[i+1:]
	}
	if obj.name == "" || obj.name == "." || obj.name == elem {
		check.softErrorf(obj, UnusedImport, "%q imported and not used", path)
	} else {

	isValid(m.Func)
	isNonNil(v.Elem().Field(0).Interface())
	isNonNil(v.Elem().Field(1).Interface())
	isNonNil(v.Elem().Field(2).Field(2).Index(0))
	isNonNil(v.Elem().FieldByName("X").Interface())
	isNonNil(v.Elem().FieldByName("Y").Interface())
	isNonNil(v.Elem().FieldByName("Z").Interface())
	isNonNil(v.Elem().FieldByName("S").Index(0).Interface())
	isNonNil(v.Type().Method(0).Func.Interface())

	// exercising https://golang.org/issues/17594
	reflect.TypeOf(os.Stdout).Elem()
	runtime.GC()
	depBase.V = depBase.F() + 1

	var c *C
	if reflect.TypeOf(F).Out(0) != reflect.TypeOf(c) {
		panic("bad reflection results, see golang.org/issue/18252")
	}

	sp := reflect.New(reflect.TypeOf(slicePtr).Elem())
	s := sp.Interface()

	if reflect.TypeOf(s) != reflect.TypeOf(slicePtr) {

		i--
	}
	return s[i+1:]
}

func toRType(t *abi.Type) rtype {
	return rtype{t}
}

func elem(t *abi.Type) *abi.Type {
	et := t.Elem()
	if et != nil {
		return et
	}
	panic("reflect: Elem of invalid type " + toRType(t).String())
}

func (t rtype) Elem() Type {
	return toType(elem(t.common()))
}

func (t rtype) In(i int) Type {
	tt := t.Type.FuncType()
	if tt == nil {

						addType(targs.At(i))
					}
				}
			}
		case *types.Pointer:
			addType(T.Elem())
		case *types.Slice:
			addType(T.Elem())
		case *types.Array:
			addType(T.Elem())
		case *types.Chan:
			addType(T.Elem())
		case *types.Map:
			addType(T.Key())
			addType(T.Elem())
		case *types.Signature:
			addType(T.Params())
			addType(T.Results())

	// declare a variable inside a function body if the variable is never used."
	check.usage(sig.scope)
}

func (check *Checker) usage(scope *Scope) {
	var unused []*Var
	for name, elem := range scope.elems {
		elem = resolve(name, elem)
		if v, _ := elem.(*Var); v != nil && !v.used {
			unused = append(unused, v)
		}
	}
	sort.Slice(unused, func(i, j int) bool {
		return cmpPos(unused[i].pos, unused[j].pos) < 0
	})

			base.Errorf("invalid operation %v (3-index slice of string)", n)
			n.SetType(nil)
			return n
		}
		n.SetType(t)
		n.SetOp(ir.OSLICESTR)
	} else if t.IsPtr() && t.Elem().IsArray() {
		tp = t.Elem()
		n.SetType(types.NewSlice(tp.Elem()))
		types.CalcSize(n.Type())
		if hasmax {
			n.SetOp(ir.OSLICE3ARR)
		} else {
			n.SetOp(ir.OSLICEARR)
		}
	} else if t.IsSlice() {
		n.SetType(t)
	} else {

// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package issue46275

type N[T any] struct {
	*N[T]
	t T
}

func (n *N[T]) Elem() T {
	return n.t
}

type I interface {
	Elem() string
}

func _() {
	var n1 *N[string]
	var _ I = n1
	type NS N[string]
	var n2 *NS
	var _ I = n2