Are D classes proper reference types?

[Ola Fosheim Grøstad]

On Friday, 25 June 2021 at 21:05:36 UTC, IGotD- wrote:
> Yes, that's a tradeoff but one I'm willing to take. I'm 
> thinking even bigger managed pointers of perhaps 32 bytes which 
> has more metadata like the allocated size. Managed languages in 
> general have fat pointers which we see everywhere and it is not 
> a big deal.

Which languages use fat pointers? C++ may use it (but is not 
required to).

> If you are littering pointers you perhaps should refactor your 
> code, use an array if loads of objects of the same type.

This is what I want to avoid as it makes refcounting more 
difficult. If D classes are reference types then they should 
always be referred to through a pointer. If you want to put it in 
an array, use a struct.

> Another thing which I'm not that satisfied with D is that there 
> is no built in method of expanding member classes into the host 
> class like C++ which creates pointer littering and memory 
> fragmentation.

Not sure what you mean by expanding? I never liked `alias this` 
for structs, inheritance would be simpler. Is this what you mean 
by expanding?

I think classes in C++ are usually used more like structs in D. 
C++ programmers tend to avoid using virtuals, so D-style classes 
(C++ classes with virtual members) tend to be a smaller part of 
C++ codebases (but it depends on the project, obviously).