tests/test-393.cs

   1 // Compiler options: -langversion:default
   2 // Test for covariance support in delegates
   3 //
   4
   5 using System;
   6
   7  public class A {
   8          protected string name;
   9
  10          public A (string name)
  11          {
  12                  this.name = "A::" + name;
  13          }
  14
  15          public A ()
  16          {
  17          }
  18
  19          public string Name {
  20                  get {
  21                          return name;
  22                  }
  23          }
  24  }
  25
  26  public class B : A {
  27          public B (string name)
  28          {
  29                  this.name = "B::" + name;
  30          }
  31
  32          public B ()
  33          {
  34          }
  35  }
  36
  37  public class C : B {
  38          public C (string name)
  39          {
  40                  this.name = "C::" + name;
  41          }
  42  }
  43
  44  public class Tester {
  45
  46          delegate A MethodHandler (string name);
  47
  48          static A MethodSampleA (string name)
  49          {
  50                  return new A (name);
  51          }
  52
  53          static B MethodSampleB (string name)
  54          {
  55                  return new B (name);
  56          }
  57
  58          static C MethodSampleC (string name)
  59          {
  60                  return new C (name);
  61          }
  62
  63          static void Main ()
  64          {
  65                  MethodHandler a = MethodSampleA;
  66                  MethodHandler b = MethodSampleB;
  67                  MethodHandler c = MethodSampleC;
  68
  69                  A instance1 = a ("Hello");
  70                  A instance2 = b ("World");
  71                  A instance3 = c ("!");
  72
  73                  Console.WriteLine (instance1.Name);
  74                  Console.WriteLine (instance2.Name);
  75                  Console.WriteLine (instance3.Name);
  76          }
  77
  78  }
  79