Add readonly to structs

OpenRA.Game/Primitives/ActionQueue.cs

@@ -65,7 +65,7 @@ namespace OpenRA.Primitives
 		}
 	}
 
-	struct DelayedAction : IComparable<DelayedAction>
+	readonly struct DelayedAction : IComparable<DelayedAction>
 	{
 		public readonly long Time;
 		public readonly Action Action;

OpenRA.Game/Primitives/BitSet.cs

@@ -75,7 +75,7 @@ namespace OpenRA.Primitives
 		}
 	}
 
-	public struct BitSet<T> : IEnumerable<string>, IEquatable<BitSet<T>> where T : class
+	public readonly struct BitSet<T> : IEnumerable<string>, IEquatable<BitSet<T>> where T : class
 	{
 		readonly BitSetIndex bits;
 

OpenRA.Game/Primitives/Color.cs

@@ -15,7 +15,7 @@ using OpenRA.Scripting;
 
 namespace OpenRA.Primitives
 {
-	public struct Color : IEquatable<Color>, IScriptBindable
+	public readonly struct Color : IEquatable<Color>, IScriptBindable
 	{
 		readonly long argb;
 

OpenRA.Game/Primitives/Int32Matrix4x4.cs

@@ -13,7 +13,7 @@ using System;
 
 namespace OpenRA
 {
-	public struct Int32Matrix4x4 : IEquatable<Int32Matrix4x4>
+	public readonly struct Int32Matrix4x4 : IEquatable<Int32Matrix4x4>
 	{
 		public readonly int M11, M12, M13, M14, M21, M22, M23, M24, M31, M32, M33, M34, M41, M42, M43, M44;
 

OpenRA.Game/Primitives/LongBitSet.cs

@@ -92,7 +92,7 @@ namespace OpenRA.Primitives
 	}
 
 	// Opitmized BitSet to be used only when guaranteed to be no more than 64 values.
-	public struct LongBitSet<T> : IEnumerable<string>, IEquatable<LongBitSet<T>> where T : class
+	public readonly struct LongBitSet<T> : IEnumerable<string>, IEquatable<LongBitSet<T>> where T : class
 	{
 		readonly long bits;
 

OpenRA.Game/Primitives/PlayerDictionary.cs

@@ -17,7 +17,7 @@ namespace OpenRA.Primitives
 	/// <summary>
 	/// Provides a mapping of players to values, as well as fast lookup by player index.
 	/// </summary>
-	public struct PlayerDictionary<T> : IReadOnlyList<T>, IReadOnlyDictionary<Player, T> where T : class
+	public readonly struct PlayerDictionary<T> : IReadOnlyList<T>, IReadOnlyDictionary<Player, T> where T : class
 	{
 		readonly T[] valueByPlayerIndex;
 		readonly Dictionary<Player, T> valueByPlayer;

OpenRA.Game/Primitives/Polygon.cs

@@ -14,13 +14,13 @@ using System.Linq;
 
 namespace OpenRA.Primitives
 {
-	public struct Polygon
+	public readonly struct Polygon
 	{
 		public static readonly Polygon Empty = new Polygon(Rectangle.Empty);
 
 		public readonly Rectangle BoundingRect;
 		public readonly int2[] Vertices;
-		bool isRectangle;
+		readonly bool isRectangle;
 
 		public Polygon(Rectangle bounds)
 		{

OpenRA.Game/Primitives/Size.cs

@@ -13,7 +13,7 @@ using System;
 
 namespace OpenRA.Primitives
 {
-	public struct Size : IEquatable<Size>
+	public readonly struct Size : IEquatable<Size>
 	{
 		public readonly int Width;
 		public readonly int Height;

OpenRA.Game/Primitives/float2.cs

@@ -18,7 +18,7 @@ namespace OpenRA
 {
 	[SuppressMessage("StyleCop.CSharp.NamingRules", "SA1300:ElementMustBeginWithUpperCaseLetter", Justification = "Mimic a built-in type alias.")]
 	[StructLayout(LayoutKind.Sequential)]
-	public struct float2 : IEquatable<float2>
+	public readonly struct float2 : IEquatable<float2>
 	{
 		public readonly float X, Y;
 

OpenRA.Game/Primitives/int2.cs

@@ -16,7 +16,7 @@ using OpenRA.Primitives;
 namespace OpenRA
 {
 	[SuppressMessage("StyleCop.CSharp.NamingRules", "SA1300:ElementMustBeginWithUpperCaseLetter", Justification = "Mimic a built-in type alias.")]
-	public struct int2 : IEquatable<int2>
+	public readonly struct int2 : IEquatable<int2>
 	{
 		public readonly int X, Y;
 		public int2(int x, int y) { X = x; Y = y; }