Simple casting?

[Taylor R Hillegeist]

On Tuesday, 26 November 2019 at 05:05:48 UTC, Taylor R Hillegeist 
wrote:
> I'm attempting to do a segment group.
>
> details:
> alias ProbePoint[3]=triple;
> triple[] irqSortedSet = UniqueTriples.keys
> 				.sort!("a[1].irqid < b[1].irqid",SwapStrategy.stable)
> 				.array;		
> 83:triple[][] irqSortedSets = irqSortedSet.chunkBy!((a,b) => 
> a[1].irqid == b[1].irqid);	
>
>
> GetAllTriplesExtractFileIrqSplit.d(83): Error: cannot 
> implicitly convert expression `chunkBy(irqSortedSet)` of type 
> `ChunkByImpl!(__lambda4, ProbePoint[3][])` to 
> `ProbePoint[3][][]`
>
> I have something that looks like a triple[][] but I can't seem 
> to get that type out.
> when I add .array it converts to a Group which doesn't make 
> sense to me because I'm not using a unary comparison. Any 
> thought?

a simpler example:

import std.algorithm.comparison : equal;
import std.array;
// Grouping by particular attribute of each element:
uint[3][] data = [
     [1, 1,0],
     [1, 2,0],
     [2, 2,0],
     [2, 3,0]
];

uint[3][][] r1 = data.chunkBy!((a,b) => a[0] == b[0]);

fails in the same way.