StructReferenceEquals

Struct.ReferenceEquals.cs

using System;
using System.Linq;
using System.Reflection;
using System.Reflection.Emit;

public static class Struct {
	public static Boolean ReferenceEquals<T>(ref T a, ref T b) where T : struct => Cache<T>.Func(ref a, ref b);

	private static class Cache<T> where T : struct {
		public delegate Boolean ReferenceEqualsDelegate(ref T a, ref T b);

		public static readonly ReferenceEqualsDelegate Func = GetReferenceEquals();

		private static ReferenceEqualsDelegate GetReferenceEquals() {
			var invokeMethodInfo = typeof(ReferenceEqualsDelegate).GetMethod(nameof(Action.Invoke));
			var returnType = invokeMethodInfo.ReturnType;
			var parameterTypes = invokeMethodInfo.GetParameters().Select(x => x.ParameterType).ToArray();
			var dynamicMethod = new DynamicMethod($"{nameof(ReferenceEquals)}_{typeof(T).Name}", returnType, parameterTypes, restrictedSkipVisibility: true);
			var ilGenerator = dynamicMethod.GetILGenerator();

			var typedReferenceValueFieldInfo = typeof(TypedReference).GetField("Value", BindingFlags.NonPublic | BindingFlags.Instance);

			ilGenerator.Emit(OpCodes.Ldarg_0);
			ilGenerator.Emit(OpCodes.Mkrefany, typeof(T));
			ilGenerator.Emit(OpCodes.Ldfld, typedReferenceValueFieldInfo);

			ilGenerator.Emit(OpCodes.Ldarg_1);
			ilGenerator.Emit(OpCodes.Mkrefany, typeof(T));
			ilGenerator.Emit(OpCodes.Ldfld, typedReferenceValueFieldInfo);

			ilGenerator.Emit(OpCodes.Call, typeof(IntPtr).GetMethod("op_Equality", new [] { typeof(IntPtr), typeof(IntPtr) }));
			ilGenerator.Emit(OpCodes.Ret);

			return (ReferenceEqualsDelegate) dynamicMethod.CreateDelegate(typeof(ReferenceEqualsDelegate));
		}
	}
}