}

// Chan contains Type fields specific to channel types.
type Chan struct {
	Elem *Type   // element type
	Dir  ChanDir // channel direction
}

// chanType returns t's extra channel-specific fields.
func (t *Type) chanType() *Chan {
	t.wantEtype(TCHAN)
	return t.extra.(*Chan)
}

type Tuple struct {
	first  *Type
	second *Type

		off += arch.PtrSize // 4 bytes, pointer aligned
	case abi.Slice: // reflect.sliceType
		off += arch.PtrSize
	case abi.Array: // reflect.arrayType
		off += 3 * arch.PtrSize
	case abi.Chan: // reflect.chanType
		off += 2 * arch.PtrSize
	case abi.Map: // reflect.mapType
		off += 4*arch.PtrSize + 8
	case abi.Interface: // reflect.interfaceType
		off += 3 * arch.PtrSize
	default:
		// just Sizeof(rtype)
	}

				}
				check.errorf(e.Key, IncomparableMapKey, "invalid map key type %s%s", typ.key, why)
			}
		}).describef(e.Key, "check map key %s", typ.key)

		return typ

	case *ast.ChanType:
		typ := new(Chan)
		setDefType(def, typ)

		dir := SendRecv
		switch e.Dir {
		case ast.SEND | ast.RECV:
			// nothing to do
		case ast.SEND:
			dir = SendOnly
		case ast.RECV:

				}
				check.errorf(e.Key, IncomparableMapKey, "invalid map key type %s%s", typ.key, why)
			}
		}).describef(e.Key, "check map key %s", typ.key)

		return typ

	case *syntax.ChanType:
		typ := new(Chan)
		setDefType(def, typ)

		dir := SendRecv
		switch e.Dir {
		case 0:
			// nothing to do
		case syntax.SendOnly:
			dir = SendOnly
		case syntax.RecvOnly:

func isTypeElem(x ast.Expr) bool {
	switch x := x.(type) {
	case *ast.ArrayType, *ast.StructType, *ast.FuncType, *ast.InterfaceType, *ast.MapType, *ast.ChanType:
		return true
	case *ast.UnaryExpr:
		return x.Op == token.TILDE
	case *ast.BinaryExpr:
		return isTypeElem(x.X) || isTypeElem(x.Y)
	case *ast.ParenExpr:
		return isTypeElem(x.X)
	}
	return false

}

// Close closes the channel v.
// It panics if v's Kind is not [Chan] or
// v is a receive-only channel.
func (v Value) Close() {
	v.mustBe(Chan)
	v.mustBeExported()
	tt := (*chanType)(unsafe.Pointer(v.typ()))
	if ChanDir(tt.Dir)&SendDir == 0 {
		panic("reflect: close of receive-only channel")
	}

	chanclose(v.pointer())
}

// ParenExpr, is correctly formatted with parens.
// Test case for issue #63362.
func TestChanType(t *testing.T) {
	expr := &ast.UnaryExpr{
		Op: token.ARROW,
		X: &ast.CallExpr{
			Fun: &ast.ChanType{
				Dir:   ast.RECV,
				Value: &ast.Ident{Name: "int"},
			},
			Args: []ast.Expr{&ast.Ident{Name: "nil"}},
		},
	}
	var buf bytes.Buffer
	if err := Fprint(&buf, fset, expr); err != nil {

		*ast.IndexExpr,
		*ast.SliceExpr,
		*ast.TypeAssertExpr,
		*ast.StarExpr,
		*ast.KeyValueExpr,
		*ast.ArrayType,
		*ast.StructType,
		*ast.FuncType,
		*ast.InterfaceType,
		*ast.MapType,
		*ast.ChanType:
		// These expression are never untyped - nothing to do.
		// The respective sub-expressions got their final types
		// upon assignment or use.
		if debug {

		*syntax.ListExpr,
		//*syntax.StarExpr,
		*syntax.KeyValueExpr,
		*syntax.ArrayType,
		*syntax.StructType,
		*syntax.FuncType,
		*syntax.InterfaceType,
		*syntax.MapType,
		*syntax.ChanType:
		// These expression are never untyped - nothing to do.
		// The respective sub-expressions got their final types
		// upon assignment or use.
		if debug {

			{DW_AT_name, DW_FORM_string},
			{DW_AT_type, DW_FORM_ref_addr},
			{DW_AT_byte_size, DW_FORM_udata},
			{DW_AT_go_kind, DW_FORM_data1},
			{DW_AT_go_runtime_type, DW_FORM_addr},
		},
	},

	/* CHANTYPE */
	{
		DW_TAG_typedef,
		DW_CHILDREN_no,
		[]dwAttrForm{
			{DW_AT_name, DW_FORM_string},
			{DW_AT_type, DW_FORM_ref_addr},
			{DW_AT_go_kind, DW_FORM_data1},
			{DW_AT_go_runtime_type, DW_FORM_addr},