Optimize GC for PropOp.Enum<T>.

Assets/Cryville/Crtr/PropOp.cs

@@ -72,19 +72,21 @@ namespace Cryville.Crtr {
 		public class Enum<T> : PropOp {
 			readonly static Dictionary<int, int> _cache = new Dictionary<int, int>();
 			readonly Action<T> _cb;
-			public Enum(Action<T> cb) {
+			readonly Func<int, T> _caster;
+			public Enum(Action<T> cb, Func<int, T> caster) {
 				if (!typeof(T).IsEnum)
 					throw new ArgumentException("Type is not enum");
 				var names = typeof(T).GetFields(BindingFlags.Public | BindingFlags.Static);
 				for (int i = 0; i < names.Length; i++)
 					_cache[IdentifierManager.SharedInstance.Request(names[i].Name)] = Convert.ToInt32(names[i].GetValue(null));
 				_cb = cb;
+				_caster = caster;
 			}
 			protected override void Execute() {
 				int result = 0;
 				for (int i = 0; i < LoadedOperandCount; i++)
 					result |= _cache[GetOperand(0).AsIdentifier()];
-				_cb((T)(object)result);
+				_cb(_caster(result));
 			}
 		}
 		public class BeatTime : PropOp {