1class Foo {
2}
3
4class FooIterator {
5	bool called = false;
6
7	public bool next () {
8		return !called;
9	}
10
11	public Foo @get () {
12		assert (!called);
13		called = true;
14		return foo_instance;
15	}
16}
17
18class FooCollection {
19	public FooIterator iterator () {
20		return new FooIterator ();
21	}
22}
23
24class FooIterator2 {
25	bool called = false;
26
27	public Foo? next_value () {
28		if (called)
29			return null;
30		called = true;
31		return foo_instance;
32	}
33}
34
35class FooCollection2 {
36	public FooIterator2 iterator () {
37		return new FooIterator2 ();
38	}
39}
40
41class FooCollection3 {
42	public int size { get { return 1; } }
43
44	public Foo @get (int index) {
45		assert (index == 0);
46		return foo_instance;
47	}
48}
49
50class FooEntry4<K,V> {
51	public K key { get; private set; }
52	public V value { get; private set; }
53
54	public FooEntry4 (K _key, V _value) {
55		key = _key;
56		value = _value;
57	}
58}
59
60class FooIterator4<G> {
61	bool called = false;
62
63	public bool next () {
64		return !called;
65	}
66
67	public G @get () {
68		assert (!called);
69		called = true;
70		return new FooEntry4<string,Foo> ("foo", foo_instance);
71	}
72}
73
74class FooCollection4<K,V> {
75	public int size { get { return 1; } }
76
77	public V @get (K key) {
78		assert (key == "foo");
79		return foo_instance;
80	}
81
82	public FooIterator4<FooEntry4<K,V>> iterator () {
83		return new FooIterator4<FooEntry4<K,V>> ();
84	}
85}
86
87Foo foo_instance;
88
89void main () {
90	foo_instance = new Foo ();
91
92	// Uses next() and get()
93	var collection = new FooCollection ();
94	foreach (var foo in collection) {
95		assert (foo == foo_instance);
96	}
97
98	// Uses next_value()
99	var collection2 = new FooCollection2 ();
100	foreach (var foo2 in collection2) {
101		assert (foo2 == foo_instance);
102	}
103
104	// Uses size and get()
105	var collection3 = new FooCollection3 ();
106	foreach (var foo3 in collection3) {
107		assert (foo3 == foo_instance);
108	}
109
110	// Uses iterator() and get()
111	var collection4 = new FooCollection4<string,Foo> ();
112	foreach (var fooentry4 in collection4) {
113		assert (fooentry4.key == "foo");
114		assert (fooentry4.value == foo_instance);
115	}
116	assert (collection4["foo"] == foo_instance);
117
118	// GLib.List
119	var list = new List<Foo> ();
120	list.append (foo_instance);
121	foreach (var e in list) {
122		assert (e == foo_instance);
123	}
124
125	// GLib.SList
126	var slist = new SList<Foo> ();
127	slist.append (foo_instance);
128	foreach (var e in slist) {
129		assert (e == foo_instance);
130	}
131}
132