I agree about internal heap allocations in stack variables. I disagree about other expensive operations happening unpredictably in constructors. If a class does something expensive in its constructor, you can generally tell by the kind of class it is. If you know the difference between identity classes and value classes - value classes may allocate but that's about it. Identity classes may be expensive (i.e. more expensive than baseline, which is writing all the memory they use once) to construct but you can generally tell.