On Tuesday, 20 August 2013 at 19:25:56 UTC, Jonathan M Davis
wrote:
On Tuesday, August 20, 2013 20:38:52 John Colvin wrote:
On Tuesday, 20 August 2013 at 17:02:07 UTC, Jonathan M Davis
wrote:
> On Tuesday, August 20, 2013 12:54:29 John Colvin wrote:
>> is there an allocation in this?
>>
>> enum vals=[1, 2, 3, 0];
>>
>> int[4] a;
>> a[] = vals[];
>
> Since, you're asking it to copy the elements of a dynamic
> array
> to a static
> one, I would fully expect it to result in an allocation,
> though
> a smart
> compiler might optimize it out. I wouldn't expect dmd to do
> that though.
>
> - Jonathan M Davis
So you're saying it will allocate a new dynamic array,
initialise
it with 1,2,3,0 and then copy the elements from that new array
to
the static one? That's not good...
Well, that's what you told it to do semantically. The compiler
could
theoretically optimize it (and hopefully will eventually), but
it would be an
optimization. At this point, if you initialize the static array
with an array
literal, then it will avoid the allocation (though it didn't
used to), but
AFAIK, it'll still allocate with your example.
- Jonathan M Davis
I presume there's a good reason why we don't have:
enum a = [1,2,3,4];
assert assert(is(typeof(a) == int[4]));
this works after all:
enum int[4] a = [1,2,3,4];
assert assert(is(typeof(a) == int[4]));
