Playing with IL generation.

FastAccessor.cs

public class FastAccessor<T> where T : class
{
	private static readonly Hashtable _cache = new Hashtable();

	public static FastAccessor<T> For(T target)
	{
		if (_cache.ContainsKey(typeof(T)))
		{
			var dlg = (Action<T, string, object>)_cache[typeof(T)];
			return new FastAccessor<T>(dlg, target);
		}
		var dlg2 = BuildDelegate<T>();
		_cache[typeof(T)] = dlg2;
		return new FastAccessor<T>(dlg2, target);
	}

	private static Action<T, string, object> BuildDelegate<T>()
	{
		var targetType = typeof(T);
		var equality = typeof(string).GetMethod("op_Equality");

		var method = IL.NewMethod()
			.WithParameter<T>("target")
			.WithParameter<string>("name")
			.WithParameter<object>("value")
			.Returns(typeof(void));

		var properties = targetType.GetProperties();
		var labels = Enumerable.Range(0, properties.Length).Select(p => $"label{p}").ToArray();
		var i = 0;
		foreach (var prop in properties)
		{
			method = method
				.Ldarg("name")
				.Ldstr(prop.Name)
				.Call(equality)
				.Brtrue(labels[i]);
			i++;
		}
		method = method.Ret();
		i = 0;
		foreach (var prop in properties)
		{
			method = method
				.MarkLabel(labels[i])
				.Ldarg("target")
				.Ldarg("value");
			if (prop.PropertyType.IsValueType)
			{
				method = method.UnboxAny(prop.PropertyType);
			}
			else
			{
				method = method.Emit(OpCodes.Castclass, prop.PropertyType);
			}
			var setter = typeof(T).GetMethod("set_" + prop.Name);
			method = method
				.Callvirt(setter)
				.Ret();
			i++;
		}

		return (Action<T, string, object>)method.AsDynamicMethod.CreateDelegate(typeof(Action<T, string, object>));
	}

	private readonly Action<T, string, object> _action;
	private readonly T _target;

	private FastAccessor(Action<T, string, object> action, T target)
	{
		_action = action;
		_target = target;
	}

	public void Set(string name, object value)
	{
		_action.Invoke(_target, name, value);
	}
}

Hi
Is there IL class in .net core ?