Structure of Arrays vs Array of Structures

[a11e99z]

On Monday, 26 August 2019 at 09:58:30 UTC, Per Nordlöw wrote:
> On Monday, 26 August 2019 at 09:54:30 UTC, Per Nordlöw wrote:
>> I have made some significant optimizations with regards to 
>> compilation performance at
>>
>> https://github.com/nordlow/phobos-next/blob/master/src/soa.d
>
> What is the preferred way to implement to support foreach over 
> `x` in
>
>     struct S { int i; float f; }
>     auto x = SOA!S();
>     foreach (S; x[])
>     {
>     }
>
> ?
>
> Implement `opSlice` that returns a SOA.Range type?

1) not sure about opSlice cuz user can allocate every time when 
he need S[..] from SOA.
   easy call for user but its too expensive op.
   maybe better to define global array( T )( SOA!T {opt: int beg, 
int end}) that returns array.
> x.array or array( x ) or x.array( 10, 20)
   looks like DRT that means "some range to newly allocated 
array". and SOA to S is some calculated range - need construct 
each element.

2) x.items returns SOA.Range