// ignore - error reported before
		case novalue:
			check.errorf(&x, NotAType, "%s used as type", &x)
		default:
			check.errorf(&x, NotAType, "%s is not a type", &x)
		}

	case *syntax.IndexExpr:
		check.verifyVersionf(e, go1_18, "type instantiation")
		return check.instantiatedType(e.X, syntax.UnpackListExpr(e.Index), def)

	case *syntax.ParenExpr:

		kind := check.rawExpr(nil, x, e.X, nil, false)
		x.expr = e
		return kind

	case *syntax.SelectorExpr:
		check.selector(x, e, nil, false)

	case *syntax.IndexExpr:
		if check.indexExpr(x, e) {
			if !enableReverseTypeInference {
				T = nil
			}
			check.funcInst(T, e.Pos(), x, e, true)
		}
		if x.mode == invalid {
			goto Error
		}

	if m := check.Instances; m != nil {
		m[ident] = Instance{newTypeList(targs), typ}
	}
}

func instantiatedIdent(expr ast.Expr) *ast.Ident {
	var selOrIdent ast.Expr
	switch e := expr.(type) {
	case *ast.IndexExpr:
		selOrIdent = e.X
	case *ast.IndexListExpr:
		selOrIdent = e.X
	case *ast.SelectorExpr, *ast.Ident:
		selOrIdent = e
	}
	switch x := selOrIdent.(type) {
	case *ast.Ident:
		return x

		m[ident] = Instance{newTypeList(targs), typ}
	}
}

func instantiatedIdent(expr syntax.Expr) *syntax.Name {
	var selOrIdent syntax.Expr
	switch e := expr.(type) {
	case *syntax.IndexExpr:
		selOrIdent = e.X
	case *syntax.SelectorExpr, *syntax.Name:
		selOrIdent = e
	}
	switch x := selOrIdent.(type) {
	case *syntax.Name:
		return x
	case *syntax.SelectorExpr:
		return x.Sel
	}

			if t.Op != syntax.Mul || t.Y != nil {
				break
			}
			ptr = true
			rtyp = t.X
		default:
			break L
		}
	}

	// unpack type parameters, if any
	if ptyp, _ := rtyp.(*syntax.IndexExpr); ptyp != nil {
		rtyp = ptyp.X
		if unpackParams {
			for _, arg := range syntax.UnpackListExpr(ptyp.Index) {
				var par *syntax.Name
				switch arg := arg.(type) {
				case *syntax.Name:
					par = arg

		case *ast.ParenExpr:
			rtyp = t.X
		case *ast.StarExpr:
			ptr = true
			rtyp = t.X
		default:
			break L
		}
	}

	// unpack type parameters, if any
	switch rtyp.(type) {
	case *ast.IndexExpr, *ast.IndexListExpr:
		ix := typeparams.UnpackIndexExpr(rtyp)
		rtyp = ix.X
		if unpackParams {
			for _, arg := range ix.Indices {
				var par *ast.Ident
				switch arg := arg.(type) {
				case *ast.Ident:

	}
	if !t.IsInterface() {
		base.Fatalf("OITAB of %v", t)
	}
	n.SetType(types.NewPtr(types.Types[types.TUINTPTR]))
	return n
}

// tcIndex typechecks an OINDEX node.
func tcIndex(n *ir.IndexExpr) ir.Node {
	n.X = Expr(n.X)
	n.X = DefaultLit(n.X, nil)
	n.X = implicitstar(n.X)
	l := n.X
	n.Index = Expr(n.Index)
	r := n.Index
	t := l.Type()
	if t == nil || r.Type() == nil {
		n.SetType(nil)

	case ir.ODOT:
		n := n.(*ir.SelectorExpr)
		if name, offset, ok = StaticLoc(n.X); !ok {
			break
		}
		offset += n.Offset()
		return name, offset, true

	case ir.OINDEX:
		n := n.(*ir.IndexExpr)
		if n.X.Type().IsSlice() {
			break
		}
		if name, offset, ok = StaticLoc(n.X); !ok {
			break
		}
		l := getlit(n.Index)
		if l < 0 {
			break
		}

		// Check for overflow.

			s.assign(left.X, new, false, 0)
			// TODO: do we need to update named values here?
			return
		}
		if left.Op() == ir.OINDEX && left.(*ir.IndexExpr).X.Type().IsArray() {
			left := left.(*ir.IndexExpr)
			s.pushLine(left.Pos())
			defer s.popLine()
			// We're assigning to an element of an ssa-able array.
			// a[i] = v
			t := left.X.Type()
			n := t.NumElem()

		if !p.isType(c.Fun) && !p.isUnsafeData(c.Fun, false) {
			break
		}
		x = c.Args[0]
	}
	u, ok := x.(*ast.UnaryExpr)
	if !ok || u.Op != token.AND {
		return false
	}
	index, ok := u.X.(*ast.IndexExpr)
	if !ok {
		return false
	}

	addr := ""
	deref := ""
	if p.isVariable(index.X) {
		addr = "&"
		deref = "*"
	}