initial

samples/CS9/CS9.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/CS9/Program.cs

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+namespace CS9 {
+  class Program {
+    // Relational patterns (>= operator et al.)
+    // Logical patterns ("or", also "and" and "not")
+    //   Note: parens ( and ) can be used to determine precedence
+    bool IsPastMidYear(DateTime dt) => dt is { Month: >= 7 };
+    bool IsThisYearOrLast(DateTime dt) => dt is { Year: 2022 or 2021 };
+    bool IsSummer(DateTime dt) => dt is
+    { Month: 7 or 8 } or
+    { Month: 6, Day: >= 21 } or
+    { Month: 9, Day: < 21 };
+
+    // Class with "Deconstruct" implementation
+    class Order {
+      public int ItemCount { get; set; }
+      public double ItemPrice { get; set; }
+      public void Deconstruct(out int itemCount, out double itemPrice) {
+        itemCount = ItemCount;
+        itemPrice = ItemPrice;
+      }
+    }
+
+    // Positional patterns with placeholders - note that
+    //   the element lists must be "complete"!
+    static OrderValue OrderValueCategory(Order o) =>
+      o switch
+      {
+        ( < 0, _) => throw new ArgumentException("Positive itemCounts please!"),
+        (_, < 0) => throw new ArgumentException("Positive itemPrices please!"),
+        ( >= 100, _) => OrderValue.ValuableDueToHighCount,
+        (_, >= 1000) => OrderValue.ValuableDueToHighItemPrice,
+
+        // Assign variable names for further processing
+        var (c, p) when c * p > 1000 => OrderValue.ValuableDueToHighTotal,
+
+        _ => OrderValue.NotValuable
+      };
+
+
+    static void Main(string[] args) {
+    }
+  }
+}