Thread overview
Unordered Element Pairs of a Range
Sep 07, 2015
Nordlöw
Sep 07, 2015
cym13
Sep 07, 2015
Nordlöw
September 07, 2015
Is there a range in Phobos for accessing all unordered combinations of a range as:

foreach (const i, const a; r)
{
    for (auto j = i + 1; j < r.length; ++j)
    {
        const b = r[j];
        // Use a and b
    }
}

excluding self-pairs, that is i != j
September 07, 2015
On Monday, 7 September 2015 at 09:06:05 UTC, Nordlöw wrote:
> Is there a range in Phobos for accessing all unordered combinations of a range as:
>
> foreach (const i, const a; r)
> {
>     for (auto j = i + 1; j < r.length; ++j)
>     {
>         const b = r[j];
>         // Use a and b
>     }
> }
>
> excluding self-pairs, that is i != j

There is an open bug for that https://issues.dlang.org/show_bug.cgi?id=6788
September 07, 2015
On Monday, 7 September 2015 at 09:12:53 UTC, cym13 wrote:
> There is an open bug for that https://issues.dlang.org/show_bug.cgi?id=6788

Thanks.

So I construct a pairwise range with two implementation cases one for RandomAccessRange and one for InputRange

https://github.com/nordlow/justd/blob/master/combinations.d#L172

Should this go into Phobos?