What is "FilterResult" type?

[deed via Digitalmars-d-learn]

On Wednesday, 9 September 2015 at 11:30:26 UTC, Bahman Movaqar 
wrote:
> On Wednesday, 9 September 2015 at 08:29:20 UTC, cym13 wrote:
>> The way I would have written it is:
>>
>> auto result = foobars.filter!(fb => nums.all!(n => (fb.x * 
>> fb.y) > n))
>>                      .filter!(fb => nums.all!(n => fb.x < n && 
>> fb.y < n));
>
> For the lame example I gave, something similar occurred to me 
> at first; but then I thought 4 `filter`s (assuming `all` is 
> simply a `filter`) might be non-idiomatic as it might incur 
> some performance penalty.

Note that this can easily be rewritten with only one `filter` and 
one `all`:

auto result = foobars.filter!(
                 fb => nums.all!(
                     n => fb.x * fb.y > n
                       && fb.x < n
                       && fb.y < n));