Add Timed to my immutable helpers

imm/Imm.cs

@@ -32,11 +32,11 @@ namespace imm
 	public record class Recorded<T> : Versioned<T>
 		where T : Recorded<T>
 	{
-		public T? Old { get; private set; }
-		public string Expression { get; private set; } = "";
-		public string MemberName { get; private set; } = "";
-		public string FilePath { get; private set; } = "";
-		public int LineNumber { get; private set; } = -1;
+		public T? Old { get; protected set; }
+		public string Expression { get; protected set; } = "";
+		public string MemberName { get; protected set; } = "";
+		public string FilePath { get; protected set; } = "";
+		public int LineNumber { get; protected set; } = -1;
 
 		public T Record(string reason = "",
 														[CallerMemberName] string memberName = "",
@@ -56,7 +56,6 @@ namespace imm
 			return newT;
 		}
 
-
 		public T Process(Func<T, T> fn, string reason = "",
 														[CallerMemberName] string memberName = "",
 														[CallerFilePath] string filePath = "",
@@ -82,12 +81,44 @@ namespace imm
 	}
 
 
+	public record class Timed<T> : Recorded<T>
+		where T : Timed<T>
+	{
+		public readonly DateTime CreatedAt = DateTime.Now;
+		public DateTime TouchedAt { get; set; } = DateTime.Now;
+
+		public T Process(Func<T, T> fn, string reason = "",
+														[CallerMemberName] string memberName = "",
+														[CallerFilePath] string filePath = "",
+														[CallerLineNumber] int lineNumber = 0,
+														[CallerArgumentExpression("fn")]
+														string expression = default)
+		{
+			var orig = (T)this;
+
+			return (T)this with
+			{
+				//Versioned
+				Version = orig.Version + 1,
+
+				//Recorded
+				Old = orig,
+				Expression = expression,
+				MemberName = memberName,
+				FilePath = filePath,
+				LineNumber = lineNumber,
+
+				TouchedAt = DateTime.Now,
+			};
+		}
+	}
+
+
 	public static class Util
 	{
 
 
 
-
 	}
 
 }