tests/gtest-054.cs

   1 //
   2 // Conversions involving type parameters (26.7.4).
   3 // This is a compilation-only test since some of the explict
   4 // conversions would trigger an InvalidCastException.
   5 //
   6
   7 using System;
   8
   9 interface Foo
  10 {
  11         void Hello ();
  12 }
  13
  14 class A
  15 { }
  16
  17 class B : A, Foo
  18 {
  19         public void Hello ()
  20         { }
  21
  22         public static implicit operator C (B b)
  23         {
  24                 return new C ();
  25         }
  26 }
  27
  28 class C
  29 {
  30         public static explicit operator B (C c)
  31         {
  32                 return new B ();
  33         }
  34 }
  35
  36 class Test
  37 {
  38         static void Simple<T> (T t)
  39         {
  40                 object o = t;
  41                 t = (T) o;
  42                 Foo foo = (Foo) t;
  43                 t = (T) foo;
  44         }
  45
  46         static void Interface<T> (T t)
  47                 where T : Foo
  48         {
  49                 Foo foo = t;
  50         }
  51
  52         static void Class<T> (T t)
  53                 where T : B
  54         {
  55                 B b = t;
  56                 A a = t;
  57                 Foo foo = t;
  58                 t = (T) b;
  59                 t = (T) a;
  60                 t = (T) foo;
  61                 C c = t;
  62                 t = (T) c;
  63         }
  64
  65         static void Array<T> (T[] t)
  66         {
  67                 object o = t;
  68                 Array a = t;
  69                 t = (T []) o;
  70                 t = (T []) a;
  71         }
  72
  73         static void Main ()
  74         { }
  75 }