initial

samples/CS7/CS7.csproj

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+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

samples/CS7/Program.cs

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+namespace CS7 {
+  public class DeadPerson {
+    public string Name { get; init; } = "";
+    public virtual bool IsAlive => false;
+  }
+
+  public class Zombie : DeadPerson {
+    public override bool IsAlive => true;
+  }
+
+  class Program {
+    static void CheckZombie(DeadPerson p) {
+      switch (p) {
+        case Zombie z:
+          Console.WriteLine($"{z.Name} is a zombie, run!");
+          break;
+        default:
+          Console.WriteLine($"Looks like {p.Name} is safe.");
+          break;
+      }
+    }
+
+    static void Main(string[] args) {
+      string s = "This is a string";
+
+      if (s is string x)
+        Console.WriteLine($"Turns out s is the string '{x}'");
+
+      var d1 = new DeadPerson { Name = "Abe Lincoln" };
+      var d2 = new Zombie { Name = "Windows 7" };
+
+      CheckZombie(d1);
+      CheckZombie(d2);
+
+      Console.WriteLine("My heartfelt apologies in case anybody finds my zombie sample offensive.");
+    }
+
+  }
+}