Unique

1 int dtor = 0;
2 static struct S
3 {
4     int num;
5     int* dtor;
6     @disable this(this){}
7     @nogc nothrow ~this()
8     {
9         if(dtor)
10             (*dtor)++;
11     }
12 }
13 
14 S s = S(200, &dtor);
15 Unique!S a = s;
16 Unique!S b;
17 
18 assert(s == S.init);
19 assert(!a.isNull);
20 assert(b.isNull);
21 assert(a.ptrUnsafe.num == 200);
22 a.access((scope ref v)
23 {
24     assert(v.num == 200);
25     v.num *= 2;
26 });
27 
28 move(a, b);
29 assert(a.isNull);
30 assert(a._value == S.init);
31 assert(!b.isNull);
32 assert(b.ptrUnsafe.num == 400);
33 
34 a = Unique!S(S(800, &dtor));
35 assert(!a.isNull);
36 assert(a.ptrUnsafe.num == 800);
37 a = null;
38 assert(a.isNull);
39 assert(a._value == S.init);
40 assert(dtor == 1);
41 
42 b.release(s);
43 assert(b.isNull);
44 assert(s.num == 400);
45 
46 a = s;
47 a.release(b);
48 assert(a.isNull);
49 assert(!b.isNull);
50 
51 void test(Unique!S s)
52 {
53     assert(!s.isNull);
54     auto ss = s.releaseRaw();
55     assert(s.isNull);
56     assert(ss.num == 400);
57 }
58 
59 test(b.release);
60 assert(dtor == 2);
61 
62 Unique!S test2(Unique!S s)
63 {
64     assert(!s.isNull);
65     return s.release;
66 }
67 
68 a = S(200, &dtor);
69 b = test2(a.release);
70 assert(dtor == 2);
71 assert(a.isNull);
72 assert(!b.isNull);
73 b.__xdtor();
74 assert(dtor == 3);