enum pointers or class references limitation

[Dmitry Olshansky via Digitalmars-d]

On Wednesday, 30 August 2017 at 12:28:10 UTC, Timon Gehr wrote:
> On 30.08.2017 11:36, Dmitry Olshansky wrote:
>> The subj is not (any longer) supported by compiler. In fact it 
>> used to produce wrong code sometimes and now it just plainly 
>> rejects it.
>> 
[..]
>
> I think the underlying reason why it does not work is that 
> dynamic array manifest constants are messed up. I.e. class 
> reference `enum`s are disallowed in order to avoid having to 
> make a decision for either inconsistent or insane semantics.

Well from my point of view enum is just evaluate this expression 
at the usage site. So any array or class instance will be created 
anew at the point of usage.

What are the problems with enums and dynamic arrays?