1Expressions in isset()
2-----
3<?php
4// This is legal.
5isset(($a), (($b)));
6// This is illegal, but not a syntax error.
7isset(1 + 1);
8-----
9array(
10    0: Stmt_Expression(
11        expr: Expr_Isset(
12            vars: array(
13                0: Expr_Variable(
14                    name: a
15                )
16                1: Expr_Variable(
17                    name: b
18                )
19            )
20        )
21        comments: array(
22            0: // This is legal.
23        )
24    )
25    1: Stmt_Expression(
26        expr: Expr_Isset(
27            vars: array(
28                0: Expr_BinaryOp_Plus(
29                    left: Scalar_Int(
30                        value: 1
31                    )
32                    right: Scalar_Int(
33                        value: 1
34                    )
35                )
36            )
37        )
38        comments: array(
39            0: // This is illegal, but not a syntax error.
40        )
41    )
42)
43