1List reference assignments (PHP 7.3)
2-----
3<?php
4
5list(&$v) = $x;
6list('k' => &$v) = $x;
7[&$v] = $x;
8['k' => &$v] = $x;
9-----
10array(
11    0: Stmt_Expression(
12        expr: Expr_Assign(
13            var: Expr_List(
14                items: array(
15                    0: ArrayItem(
16                        key: null
17                        value: Expr_Variable(
18                            name: v
19                        )
20                        byRef: true
21                        unpack: false
22                    )
23                )
24            )
25            expr: Expr_Variable(
26                name: x
27            )
28        )
29    )
30    1: Stmt_Expression(
31        expr: Expr_Assign(
32            var: Expr_List(
33                items: array(
34                    0: ArrayItem(
35                        key: Scalar_String(
36                            value: k
37                        )
38                        value: Expr_Variable(
39                            name: v
40                        )
41                        byRef: true
42                        unpack: false
43                    )
44                )
45            )
46            expr: Expr_Variable(
47                name: x
48            )
49        )
50    )
51    2: Stmt_Expression(
52        expr: Expr_Assign(
53            var: Expr_List(
54                items: array(
55                    0: ArrayItem(
56                        key: null
57                        value: Expr_Variable(
58                            name: v
59                        )
60                        byRef: true
61                        unpack: false
62                    )
63                )
64            )
65            expr: Expr_Variable(
66                name: x
67            )
68        )
69    )
70    3: Stmt_Expression(
71        expr: Expr_Assign(
72            var: Expr_List(
73                items: array(
74                    0: ArrayItem(
75                        key: Scalar_String(
76                            value: k
77                        )
78                        value: Expr_Variable(
79                            name: v
80                        )
81                        byRef: true
82                        unpack: false
83                    )
84                )
85            )
86            expr: Expr_Variable(
87                name: x
88            )
89        )
90    )
91)
92