implementing IEquatable, calm nullable warnings

Author: DGrothe-PhD

src/Evaluation.cs

@@ -1,8 +1,9 @@
 using Lang;
+using System.Diagnostics.CodeAnalysis;
 
 namespace MastermindVariante
 {
-    public struct Points : IComparable<Points>
+    public readonly struct Points : IComparable<Points>, IEquatable<Points>
     {
         public short blackpins { get; init; }
         public short whitepins { get; init; }
@@ -13,13 +14,36 @@ public Points(short blacks, short whites)
             this.whitepins = whites;
         }
 
-        public int CompareTo(Points other)
+        public readonly int CompareTo(Points other)
         {
             if (this.blackpins < other.blackpins) return -1;
             if (this.blackpins == other.blackpins)
                 return this.whitepins.CompareTo(other.whitepins);
             else return 1;
         }
+
+        public readonly bool Equals(Points other)
+        {
+            return other is Points p && p.blackpins == blackpins && p.whitepins == whitepins;
+        }
+
+        public readonly override bool Equals(object? obj)
+            => obj is Points objS && Equals(objS);
+
+        public static bool operator== (Points a, Points b)
+        {
+            return a.Equals(b);
+        }
+
+        public static bool operator!= (Points a, Points b)
+        {
+            return !(a == b);
+        }
+
+        public override readonly int GetHashCode()
+        {
+            return HashCode.Combine(blackpins, whitepins);
+        }
     }
     public class Evaluation
     {

src/GuessedRow.cs

@@ -3,6 +3,7 @@
     public partial class GuessedRow : Parameter, ILetters, IMMDispose
     {
         private static short rowIndex = -1;
+
         internal static Form1? Caller { get; private set; }
         private readonly List<Piece> pieces;
         private readonly List<ResultPin> pins;
@@ -32,8 +33,8 @@ public GuessedRow(Form1 _caller)
 
             for (short i = 0; i < level; i++)
             {
-                pieces.Add(new Piece(Caller, rowIndex, i));
-                pins.Add(new ResultPin(Caller, rowIndex, i));
+                pieces.Add(new Piece(Caller!, rowIndex, i));
+                pins.Add(new ResultPin(Caller!, rowIndex, i));
             }
 
             FormatObjects();
@@ -114,7 +115,7 @@ internal bool Calculate()
             {
                 foreach (var x in pieces)
                 {
-                    if (!(ExcludedChars!.Contains(x.GetLetter()[0])))
+                    if (!ExcludedChars!.Contains(x.GetLetter()[0]))
                     {
                         ExcludedChars.Add(x.GetLetter()[0]);
                     }