mcs/tests/gtest-variance-11.cs

   1 using System;
   2
   3 interface IContravariant<in T>
   4 {
   5 }
   6
   7 interface ICovariant<out T>
   8 {
   9 }
  10
  11 class D
  12 {
  13         public static bool Contra<T> (IContravariant<T> e1, IContravariant<T> e2)
  14         {
  15                 Console.WriteLine (typeof (T));
  16                 return typeof (T) == typeof (string);
  17         }
  18
  19         public static bool Covariant<T> (ICovariant<T> e1, ICovariant<T> e2)
  20         {
  21                 Console.WriteLine (typeof (T));
  22                 return typeof (T) == typeof (object);
  23         }
  24
  25         public static bool CovContCont<T> (ICovariant<T> e1, IContravariant<T> e2, IContravariant<T> e3)
  26         {
  27                 Console.WriteLine (typeof (T));
  28                 return typeof (T) == typeof (string);
  29         }
  30
  31         public static bool ContCovContCov<T> (IContravariant<T> e1, ICovariant<T> e2, IContravariant<T> e3, ICovariant<T> e4)
  32         {
  33                 Console.WriteLine (typeof (T));
  34                 return typeof (T) == typeof (string);
  35         }
  36
  37         public static bool CovCovCont<T> (ICovariant<T> e1, ICovariant<T> e2, IContravariant<T> e3)
  38         {
  39                 Console.WriteLine (typeof (T));
  40                 return typeof (T) == typeof (string);
  41         }
  42
  43         public static int Main ()
  44         {
  45
  46                 ICovariant<object> a = null;
  47                 ICovariant<string> b = null;
  48                 if (!Covariant (a, b))
  49                         return 1;
  50
  51                 IContravariant<string> a_1 = null;
  52                 IContravariant<object> b_1 = null;
  53                 if (!Contra (a_1, b_1))
  54                         return 2;
  55
  56                 ICovariant<string> a_2 = null;
  57                 IContravariant<object> b_2 = null;
  58                 IContravariant<string> c_2 = null;
  59                 if (!CovContCont (a_2, b_2, c_2))
  60                         return 3;
  61
  62                 IContravariant<object> a_3 = null;
  63                 ICovariant<string> b_3 = null;
  64                 IContravariant<string> c_3 = null;
  65                 ICovariant<string> d_3 = null;
  66                 if (!ContCovContCov (a_3, b_3, c_3, d_3))
  67                         return 4;
  68
  69                 Console.WriteLine ("ok");
  70                 return 0;
  71         }
  72 }