IntrusivePtr.exchange

1 static struct Foo{
2     ControlBlock!(int, int) c;
3     int i;
4 
5     this(int i)pure nothrow @safe @nogc{
6         this.i = i;
7     }
8 }
9 
10 //lvalue exchange
11 {
12     shared x = IntrusivePtr!(shared Foo).make(123);
13     auto y = IntrusivePtr!(shared Foo).make(42);
14 
15     auto z = x.exchange(y);
16 
17     assert(x.load.get.i == 42);
18     assert(y.get.i == 42);
19     assert(z.get.i == 123);
20 }
21 
22 //rvalue exchange
23 {
24     shared x = IntrusivePtr!(shared Foo).make(123);
25     auto y = IntrusivePtr!(shared Foo).make(42);
26 
27     import core.lifetime : move;
28     auto z = x.exchange(move(y));
29 
30     assert(x.load.get.i == 42);
31     assert(y == null);
32     assert(z.get.i == 123);
33 }
34 
35 //null exchange (same as move)
36 {
37     shared x = IntrusivePtr!(shared Foo).make(123);
38 
39     auto z = x.exchange(null);
40 
41     assert(x.load == null);
42     assert(z.get.i == 123);
43 }
44 
45 //swap:
46 {
47     shared x = IntrusivePtr!(shared Foo).make(123);
48     auto y = IntrusivePtr!(shared Foo).make(42);
49 
50     //opAssign is same as store
51     import core.lifetime : move;
52     y = x.exchange(move(y));
53 
54     assert(x.load.get.i == 42);
55     assert(y.get.i == 123);
56 }