Merge pull request #13 from AnnulusGames/implement-iequatable

Change: implements IEquatable<T>

Author: nuskey8

src/Arch.Unity/Assets/Arch.Unity/Runtime/Conversion/GameObjectDisabled.cs

@@ -1,4 +1,12 @@
+using System;
+
 namespace Arch.Unity.Conversion
 {
-    public readonly struct GameObjectDisabled { }
+    public readonly struct GameObjectDisabled : IEquatable<GameObjectDisabled>
+    {
+        public bool Equals(GameObjectDisabled other) => true;
+        public override bool Equals(object obj) => obj is GameObjectDisabled;
+        public override int GetHashCode() => 0;
+        public override string ToString() => "()";
+    }
 }

src/Arch.Unity/Assets/Arch.Unity/Runtime/Conversion/GameObjectReference.cs

@@ -1,14 +1,31 @@
+using System;
 using UnityEngine;
 
 namespace Arch.Unity.Conversion
 {
-    public readonly struct GameObjectReference
+    public readonly struct GameObjectReference : IEquatable<GameObjectReference>
     {
         public GameObjectReference(GameObject gameObject)
         {
             this.GameObject = gameObject;
         }
 
         public readonly GameObject GameObject;
+
+        public bool Equals(GameObjectReference other)
+        {
+            return other.GameObject == GameObject;
+        }
+
+        public override bool Equals(object obj)
+        {
+            if (obj is GameObjectReference reference) return Equals(reference);
+            return false;
+        }
+
+        public override int GetHashCode()
+        {
+            return GameObject.GetHashCode();
+        }
     }
 }

src/Arch.Unity/Assets/Arch.Unity/Runtime/Toolkit/SystemState.cs

@@ -1,8 +1,26 @@
+using System;
+
 namespace Arch.Unity.Toolkit
 {
-    public struct SystemState
+    public struct SystemState : IEquatable<SystemState>
     {
         public float DeltaTime;
         public double Time;
+
+        public readonly bool Equals(SystemState other)
+        {
+            return other.DeltaTime == DeltaTime && other.Time == Time;
+        }
+
+        public override readonly bool Equals(object obj)
+        {
+            if (obj is SystemState state) return Equals(state);
+            return false;
+        }
+
+        public override readonly int GetHashCode()
+        {
+            return HashCode.Combine(DeltaTime, Time);
+        }
     }
 }