Is there a way to tell D to rearrange struct members or to not rearrange class members?

[WraithGlade via Digitalmars-d-learn]

I've read both of the available printed D books in their entirety 
(Ali's and Andrei's) and I noticed Andrei's book (circa ~2010) 
mentions that the D compiler rearranges the members of `class` 
objects to be more optimal by reducing alignment-induced padding 
whereas it leaves the alignment-induced padding of `struct` 
objects exactly the same as implied and required by the order in 
which you've written the members of the struct.

So, the question here is, is there a way to make the D compiler 
change that behavior per specific `class` and `struct` type 
definitions or at least across the whole compilation?

I looked in the `pragma` section in the D library documentation 
but didn't find it and didn't find it elsewhere either (e.g. it 
wasn't in the `man` page for DMD).

Does anyone know if such memory arrangement control is possible 
currently?

It isn't a major problem at all (easy to work around, such as by 
embedding a `struct` in a class for `class`s, or manually 
reordering `struct` members for `struct`s), but I was just 
curious.

Thanks for reading, as always!