sizeof() equivalent for reference types?

Question

I'm looking for a way to get the size of an instance of a reference type. sizeof is only for value types. Is this possible?

Answer 1

You need Marshal.SizeOf

Edit: This is for unsafe code, but then, so is sizeof().

Answer 2

Beware that Marshal.SizeOf is for unsafe code...

I don't think it's possible for managed code though, maybe you can explain your problem, there may be another way to solve it

Answer 3

It's not a problem, just a curiosity exercise. I have a bunch of items going into HttpContext.Items throughout a request, and I was just curious how much memory they were taking up (if it even matters). I'm going through a "measure everything" phase.

Answer 4

If you don't mind it being a little less accurate than perfect, and for comparative purposes, you could serialize the object/s and measure that (in bytes for example)

EDIT (I kept thinking after posting): Because it's a little more complicated than sizeof for valuetypes, for example: reference types can have references to other objects and so on... there's not an exact and easy way to do it that I know of...