Add code example for CA2226 rule (#49086)

docs/fundamentals/code-analysis/quality-rules/ca2226.md

@@ -10,6 +10,8 @@ helpviewer_keywords:
   - "CA2226"
 author: gewarren
 ms.author: gewarren
+dev_langs:
+- CSharp
 ---
 # CA2226: Operators should have symmetrical overloads
 
@@ -37,6 +39,16 @@ The C# compiler issues an error for violations of this rule.
 
 To fix a violation of this rule, implement both the equality and inequality operators, or remove the one that's present.
 
+## Example
+
+The following example shows a sturct that violates this rule.
+
+:::code language="csharp" source="snippets/csharp/all-rules/ca2226.cs" id="snippet1":::
+
+The following example fixes the violation by adding the `!=`, `>` and `<=` operators.
+
+:::code language="csharp" source="snippets/csharp/all-rules/ca2226.cs" id="snippet2":::
+
 ## When to suppress warnings
 
 Do not suppress a warning from this rule. If you do, your type will not work in a manner that's consistent with .NET.

docs/fundamentals/code-analysis/quality-rules/snippets/csharp/all-rules/ca2226.cs

@@ -0,0 +1,75 @@
+using System;
+
+namespace ca2226
+{
+    //<snippet1>
+    // This struct violates the rule.
+    public struct Point
+    {
+        public Point(int x, int y)
+        {
+            X = x;
+            Y = y;
+        }
+
+        public int X { get; }
+        public int Y { get; }
+
+        public override int GetHashCode() => HashCode.Combine(X, Y);
+
+        // CA2226: Since 'Point' redefines operator '==', it should also redefine operator '!='
+        public static bool operator ==(Point left, Point right)
+            => left.X == right.X && left.Y == right.Y;
+
+        // CA2226: Since 'Point' redefines operator '<', it should also redefine operator '>'
+        public static bool operator <(Point left, Point right)
+            => left.DistanceFromOrigin() < right.DistanceFromOrigin();
+
+        // CA2226: Since 'Point' redefines operator '>=', it should also redefine operator '<='
+        public static bool operator >=(Point left, Point right)
+            => left.DistanceFromOrigin() >= right.DistanceFromOrigin();
+
+        private double DistanceFromOrigin() => Math.Sqrt(X * X + Y * Y);
+    }
+    //</snippet1>
+}
+
+namespace ca2226_2
+{
+    //<snippet2>
+    // This struct satisfies the rule.
+    public struct Point
+    {
+        public Point(int x, int y)
+        {
+            X = x;
+            Y = y;
+        }
+
+        public int X { get; }
+        public int Y { get; }
+
+        public override int GetHashCode() => HashCode.Combine(X, Y);
+
+        public static bool operator ==(Point left, Point right)
+            => left.X == right.X && left.Y == right.Y;
+
+        public static bool operator !=(Point left, Point right)
+            => !(left == right);
+
+        public static bool operator <(Point left, Point right)
+            => left.DistanceFromOrigin() < right.DistanceFromOrigin();
+
+        public static bool operator >(Point left, Point right)
+            => left.DistanceFromOrigin() > right.DistanceFromOrigin();
+
+        public static bool operator >=(Point left, Point right)
+            => left.DistanceFromOrigin() >= right.DistanceFromOrigin();
+
+        public static bool operator <=(Point left, Point right)
+            => left.DistanceFromOrigin() <= right.DistanceFromOrigin();
+
+        private double DistanceFromOrigin() => Math.Sqrt(X * X + Y * Y);
+    }
+    //</snippet2>
+}