Use readonly struct.

Author: bgrainger

src/MySqlConnector/Protocol/PayloadData.cs

@@ -3,7 +3,7 @@
 
 namespace MySqlConnector.Protocol
 {
-	internal struct PayloadData : IDisposable
+	internal readonly struct PayloadData : IDisposable
 	{
 		public PayloadData(byte[] data, bool isPooled = false)
 		{

src/MySqlConnector/Protocol/Serialization/Packet.cs

@@ -2,7 +2,7 @@
 
 namespace MySqlConnector.Protocol.Serialization
 {
-	internal struct Packet
+	internal readonly struct Packet
 	{
 		public Packet(ArraySegment<byte> contents)
 		{

src/MySqlConnector/Utilities/ResizableArraySegment.cs

@@ -5,7 +5,7 @@ namespace MySqlConnector.Utilities
 	/// <summary>
 	/// An <see cref="ArraySegment{T}"/> that supports having its underlying array reallocated and resized.
 	/// </summary>
-	internal struct ResizableArraySegment<T>
+	internal readonly struct ResizableArraySegment<T>
 	{
 		public ResizableArraySegment(ResizableArray<T> array, int offset, int count)
 		{

src/MySqlConnector/Utilities/TimerQueue.cs

@@ -108,7 +108,7 @@ private void UnsafeClearTimer()
 			m_timer.Change(-1, -1);
 		}
 
-		private struct Data
+		private readonly struct Data
 		{
 			public Data(uint id, int time, Action action)
 			{