C++17 cannot beat D surely

[Mike Parker via Digitalmars-d]

On Sunday, 4 June 2017 at 04:39:21 UTC, Adam D. Ruppe wrote:
> On Sunday, 4 June 2017 at 04:34:44 UTC, Mike Parker wrote:
>> I would not have expected enum b = sort(a) to trigger an 
>> allocation. auto b, yes, of course (and the disassembly from 
>> that is not much different). So I'd love to see a blog post 
>> explaining it.
>
> I don't think I can do a full-on blog post, but I can answer it 
> in a couple sentences: `enum` is treated by the compiler just 
> like literals. Array literals allocate at each usage point, 
> therefore enum arrays allocate at each usage point. (*each* 
> usage point)

Right, but I was under the impression that was only for direct 
use of the enum literal:

enum a = [1, 2, 3];
auto b = a;

I thought that assigning the result of a function call to an enum 
would force a compile-time evaluation of the function, so I would 
expect enum b = call(lit) to be identical to static immutable b = 
call(lit).