mono/tests/delegate14.cs

   1 using System;
   2
   3 // Regression test for bug #58888
   4
   5 public static class Program
   6 {
   7         public static int Main (string[] args)
   8         {
   9                 // calling delegate on extension method with null target is allowed
  10                 Func<int> func = null;
  11                 if (CallFunc(func.CallFuncIfNotNull) != 0)
  12                         return 2;
  13
  14                 // constructing delegate on instance method with null target should throw
  15                 ITest obj = null;
  16                 try
  17                 {
  18                         GC.KeepAlive((Action)obj.Func);
  19                 }
  20                 catch (NullReferenceException)
  21                 {
  22                         return 0;
  23                 }
  24
  25                 return 1;
  26         }
  27
  28         interface ITest
  29         {
  30                 void Func ();
  31         }
  32
  33         static int CallFunc(Func<int> func)
  34         {
  35                 return func();
  36         }
  37 }
  38
  39 public static class FuncExtensions
  40 {
  41         public static int CallFuncIfNotNull(this Func<int> func)
  42         {
  43                 if (func != null)
  44                         return func();
  45
  46                 return 0;
  47         }
  48 }