mcs/tests/test-pattern-09.cs

   1 using System.Collections.Generic;
   2
   3 class Expr
   4 {
   5         public int Field;
   6 }
   7
   8 static class X
   9 {
  10         public static IEnumerable<int> Test (Expr expr)
  11         {
  12                 object exprCur = expr;
  13                 if (exprCur is Expr list) {
  14                         yield return list.Field;
  15                 }
  16         }
  17
  18         public static IEnumerable<string> Test2 (int? expr)
  19         {
  20                 int? exprCur = expr;
  21                 while (exprCur != null) {
  22                         if (exprCur is int list) {
  23                                 yield return list.ToString ();
  24                         }
  25                 }
  26         }
  27
  28         public static void Main ()
  29         {
  30                 Test (null);
  31                 Test2 (3);
  32         }
  33 }