Heap: container or range?

[Andrei Alexandrescu]

Sean Kelly wrote:
> Sean Kelly wrote:
>> Andrei Alexandrescu wrote:
>>>
>>> Ah, never mind all that. I realized that I can't have a heap range. 
>>> This is because heaps must mutate the underlying range in-place and 
>>> any copy will mess the heap up. Here's the example that clarify it 
>>> for me:
>>>
>>>         int[] a = [ 4, 1, 3, 2, 16, 9, 10, 14, 8, 7 ];
>>>         auto h = Heap!(int[])(a);
>>>         assert(equal(take(5, h) == [ 8, 9, 10, 14, 16 ]);
>>>
>>> At this point the mutations done by take messed up h already!!
>>
>> Hm... so assuming this is a min heap, I have:
>>
>> a = [4,1,3,2,16,9,10,14,8,7];
>> h = [1,2,3,4,7,9,10,14,8,16];
>> take(5, h);
>> h = [8,10,9,16,14];
>>
>> Shouldn't take call next repeatedly on the heap, which will in turn 
>> perform a popHeap operation?  It's difficult to be sure what the 
>> result will be after take(5,h) occurs, but it should still be a valid 
>> heap, correct?
> 
> Oh, I would also expect:
> 
> a = [8,10,9,16,14, garbage];
> 
> Since it isn't aware of the length adjustment.  Perhaps this is what you 
> meant?
> 
> 
> Sean

Yah, that's what I meant. h still thinks its length is 10 and that those 
10 elements respect the heap property.

Andrei