What would break if class was merged with struct

[Ola Fosheim Grøstad via Digitalmars-d]

On Saturday, 27 May 2017 at 17:19:48 UTC, Moritz Maxeiner wrote:
> On Saturday, 27 May 2017 at 17:02:40 UTC, Ola Fosheim Grøstad 
> wrote:
>
>>
>> The class reference type should be fixable with a rewrite into 
>> templated smart pointers, so no need for big changes there, I 
>> think.
>
> Smart pointers impose a specific object lifetime, whereas (D) 
> classes do not. You cannot lower (D) class instances to smart 
> pointers.

In this context smart pointers are just pointers that aren't raw 
pointers, e.g. alias this or something.