x = t
	}
	return x
}

func (p *parser) embeddedTerm() ast.Expr {
	if p.trace {
		defer un(trace(p, "EmbeddedTerm"))
	}
	if p.tok == token.TILDE {
		t := new(ast.UnaryExpr)
		t.OpPos = p.pos
		t.Op = token.TILDE
		p.next()
		t.X = p.parseType()
		return t
	}

	t := p.tryIdentOrType()
	if t == nil {
		pos := p.pos
		p.errorExpected(pos, "~ term or type")

}

// EmbeddedTerm = [ "~" ] Type .
func (p *parser) embeddedTerm() Expr {
	if trace {
		defer p.trace("embeddedTerm")()
	}

	if p.tok == _Operator && p.op == Tilde {
		t := new(Operation)
		t.pos = p.pos()
		t.Op = Tilde
		p.next()
		t.X = p.type_()
		return t
	}

	t := p.typeOrNil()
	if t == nil {
		t = p.badExpr()
		p.syntaxError("expected ~ term or type")

			x.mode = invalid
			return
		}

		x.mode = commaok
		x.typ = ch.elem
		check.hasCallOrRecv = true
		return

	case token.TILDE:
		// Provide a better error position and message than what check.op below would do.
		if !allInteger(x.typ) {
			check.error(e, UndefinedOp, "cannot use ~ outside of interface or type constraint")
			x.mode = invalid

			x.mode = invalid
			return
		}
		x.mode = commaok
		x.typ = ch.elem
		check.hasCallOrRecv = true
		return

	case syntax.Tilde:
		// Provide a better error position and message than what check.op below would do.
		if !allInteger(x.typ) {
			check.error(e, UndefinedOp, "cannot use ~ outside of interface or type constraint")
			x.mode = invalid

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
}

func (p *printer) signature(sig *ast.FuncType) {