One thing I like about F# is the ability to use readonly objects in a way that does not require a lot of code. I’ve done a small lib inspired by this ability of F#: with The syntax is a bit special since I assume that the properties have a private set. versions prior to 5 myobject.With(m => m.Property1 == 3 && m.Property2 == "3") With 5+ using With; ... public class SomeClass { private static readonly IPreparedCopy<MyClass, int, string> PreparedCopy = Prepare.Copy<MyClass, int, string>((m[...]