libphobos/testsuite/libphobos.exceptions/refcounted.d

   1 // { dg-options "-fpreview=dip1008" }
   2 class E : Exception
   3 {
   4     static int instances;
   5     this(string msg = "", Throwable nextInChain = null)
   6     {
   7         super(msg, nextInChain);
   8         instances++;
   9     }
  10
  11     ~this()
  12     {
  13         instances--;
  14     }
  15 }
  16
  17 void main()
  18 {
  19     alias chain = Exception.chainTogether;
  20
  21     assert(chain(null, null) is null);
  22
  23     try
  24     {
  25         throw new E();
  26     }
  27     catch (E e)
  28     {
  29         assert(E.instances == 1);
  30         assert(e.refcount == 2);
  31     }
  32
  33     assert(E.instances == 0);
  34
  35     try
  36     {
  37         throw new E();
  38     }
  39     catch (E e)
  40     {
  41         assert(chain(null, e) is e);
  42         assert(e.refcount == 2); // "Owned by e" + 1
  43     }
  44
  45     assert(E.instances == 0);
  46
  47     try
  48     {
  49         throw new E();
  50     }
  51     catch (E e)
  52     {
  53         assert(chain(e, null) is e);
  54         assert(e.refcount == 2); // "Owned by e" + 1
  55     }
  56
  57     assert(E.instances == 0);
  58
  59     try
  60     {
  61         throw new E("first");
  62     }
  63     catch (E first)
  64     {
  65         try
  66         {
  67             throw new E("second");
  68         }
  69         catch (E second)
  70         {
  71             try
  72             {
  73                 throw new E("third");
  74             }
  75             catch (E third)
  76             {
  77                 assert(chain(first, second) is first);
  78                 assert(first.next is second);
  79                 assert(second.next is null);
  80
  81                 assert(chain(first, third) is first);
  82                 assert(first.next is second);
  83                 assert(second.next is third);
  84                 assert(third.next is null);
  85
  86                 assert(first.refcount == 2);
  87                 assert(second.refcount == 3);
  88                 assert(third.refcount == 3);
  89             }
  90         }
  91
  92         assert(E.instances == 3);
  93     }
  94
  95     assert(E.instances == 0);
  96
  97     try
  98     {
  99         throw new E("first");
 100     }
 101     catch (E first)
 102     {
 103         assert(first.refcount == 2);
 104         assert(E.instances == 1);
 105
 106         try
 107         {
 108             throw new E("second", first);
 109         }
 110         catch (E second)
 111         {
 112             assert(first.next is null);
 113             assert(second.next is first);
 114
 115             assert(first.refcount == 3);
 116             assert(second.refcount == 2);
 117
 118             assert(E.instances == 2);
 119         }
 120
 121         assert(first.refcount == 2);
 122         assert(E.instances == 1);
 123     }
 124
 125     assert(E.instances == 0);
 126 }