mcs/tests/test-395.cs

   1 // Compiler options: -langversion:default
   2 //
   3 // Test for contravariance support in delegates
   4 //
   5
   6 using System;
   7
   8  public class A {
   9          protected string name;
  10
  11          public A (string name)
  12          {
  13                  this.name = "A::" + name;
  14          }
  15
  16          public A ()
  17          {
  18          }
  19
  20          public string Name {
  21                  get {
  22                          return name;
  23                  }
  24          }
  25  }
  26
  27  public class B : A {
  28          public B (string name)
  29          {
  30                  this.name = "B::" + name;
  31          }
  32
  33          public B ()
  34          {
  35          }
  36  }
  37
  38  public class C : B {
  39          string value;
  40
  41          public C (string name, string value)
  42          {
  43                  this.name = "C::" + name;
  44                  this.value = value;
  45          }
  46
  47          public string Value {
  48                  get {
  49                          return value;
  50                  }
  51          }
  52  }
  53
  54  public class Tester {
  55
  56          delegate void MethodHandler (C c1, C c2, C c3);
  57
  58          static void MethodSample (B b, A a, C c)
  59          {
  60                  Console.WriteLine ("b = {0}", b.Name);
  61                  Console.WriteLine ("a = {0}", a.Name);
  62                  Console.WriteLine ("c = {0}, {1}", c.Name, c.Value);
  63          }
  64
  65          public static void Main ()
  66          {
  67                  MethodHandler mh = MethodSample;
  68
  69                  C a = new C ("Hello", "hello");
  70                  C b = new C ("World", "world");
  71                  C c = new C ("!", "!!!");
  72
  73                  mh (b, a, c);
  74          }
  75
  76  }
  77