Binary heap: obtain a _reference_ to the front of the heap

[Johan Engelen via Digitalmars-d-learn]

On Tuesday, 13 September 2016 at 08:55:15 UTC, Nicholas Wilson 
wrote:
> On Tuesday, 13 September 2016 at 08:19:04 UTC, Johan Engelen 
> wrote:
>> In the binary heap documentation, I read that 
>> `BinaryHeap.front()` "Returns a copy of the front of the 
>> heap". [1]
>> Is there no function to access the front of the heap without a 
>> copy?  (micro-optimization)
>>
>> Thanks,
>>   Johan
>>
>> [1] 
>> https://dlang.org/phobos/std_container_binaryheap.html#.BinaryHeap.front
>
> What does
> foreach(ref e; bh)
> {
>      //...
> }
> do?

It copies the front of the heap on every iteration.