Definately fixed-size arrays should be in base. The question is a little 
how this interacts with NTuple, which (if I understand this correctly) also 
be at some point "tight" fixed-size vectors. 

Am Donnerstag, 8. Mai 2014 11:03:08 UTC+2 schrieb Carlos Becker:
>
> Thanks, that's great!
>
> Maybe this should make it to upstream julia.
> Fixed-size arrays are essential to get good performance, and compact 
> memory usage.
>
>
> ------------------------------------------
> Carlos
>  
>
> On Wed, May 7, 2014 at 5:46 PM, Tobias Knopp 
> <[email protected]<javascript:>
> > wrote:
>
>> see https://github.com/JuliaLang/julia/issues/5857. I have been using 
>> ImmutableArrays.jl which works fine.
>>
>> Am Mittwoch, 7. Mai 2014 17:12:04 UTC+2 schrieb Carlos Becker:
>>
>>> Hello, I am trying to find out the best way to deal with immutables (or 
>>> types) that contain fixed-size arrays, such as this:
>>>
>>> # should have variable number of
>>>
>>> # Uint64's
>>>
>>> immutable Descriptor
>>>
>>>    a1::Uint64 
>>>
>>>    a2::Uint64 
>>>
>>>    a3::Uint64 
>>>
>>>    a4::Uint64
>>>
>>> end
>>>
>>> # should work with variable-size Descriptor
>>>
>>> function myDist(x1::Descriptor,x2::Descriptor) :inline
>>>
>>>     return count_ones(x1.a1 $ x2.a1) + count_ones(x1.a2 $ x2.a2) + 
>>> count_ones(x1.a3 $ x2.a3) + count_ones(x1.a4 $ x2.a4)
>>>
>>> end
>>>
>>>
>>>
>>> In this specific case, Descriptor is 32-bytes wide, but I would like to 
>>> make the code generic for different number of elements in the immutable.
>>> If fixed-size arrays were available, this would be very easy, but which 
>>> is a neat way of doing this with the current julia v0.3?
>>>
>>> btw, the code above runs amazingly fast, using popcount instructions 
>>> when available, almost c-speed ;)
>>> This is good news for Julia indeed.
>>>
>>> Thanks.
>>>
>>
>

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