// resulting in 2 or more values; otherwise we have an assignment mismatch.
	if r != 1 {
		// Only report a mismatch error if there are no other errors on the lhs or rhs.
		okLHS := check.useLHS(lhs...)
		okRHS := check.use(orig_rhs...)
		if okLHS && okRHS {
			check.assignError(orig_rhs, l, r)
		}
		return
	}

	rhs, commaOk := check.multiExpr(orig_rhs[0], l == 2)
	r = len(rhs)

	// resulting in 2 or more values; otherwise we have an assignment mismatch.
	if r != 1 {
		// Only report a mismatch error if there are no other errors on the lhs or rhs.
		okLHS := check.useLHS(lhs...)
		okRHS := check.use(orig_rhs...)
		if okLHS && okRHS {
			check.assignError(orig_rhs, l, r)
		}
		return
	}

	rhs, commaOk := check.multiExpr(orig_rhs[0], l == 2)
	r = len(rhs)

func (check *Checker) use(args ...ast.Expr) bool { return check.useN(args, false) }

// useLHS is like use, but doesn't "use" top-level identifiers.
// It should be called instead of use if the arguments are
// expressions on the lhs of an assignment.
func (check *Checker) useLHS(args ...ast.Expr) bool { return check.useN(args, true) }

func (check *Checker) useN(args []ast.Expr, lhs bool) bool {
	ok := true

func (check *Checker) use(args ...syntax.Expr) bool { return check.useN(args, false) }

// useLHS is like use, but doesn't "use" top-level identifiers.
// It should be called instead of use if the arguments are
// expressions on the lhs of an assignment.
func (check *Checker) useLHS(args ...syntax.Expr) bool { return check.useN(args, true) }

func (check *Checker) useN(args []syntax.Expr, lhs bool) bool {

		// declaration, but the post statement must not."
		if s, _ := s.Post.(*ast.AssignStmt); s != nil && s.Tok == token.DEFINE {
			check.softErrorf(s, InvalidPostDecl, "cannot declare in post statement")
			// Don't call useLHS here because we want to use the lhs in
			// this erroneous statement so that we don't get errors about
			// these lhs variables being declared and not used.
			check.use(s.Lhs...) // avoid follow-up errors
		}