How can I use heapify in @safe code?

[Burt via Digitalmars-d-learn]

On Saturday, 1 October 2016 at 18:36:54 UTC, klmp wrote:
> On Saturday, 1 October 2016 at 16:59:18 UTC, Burt wrote:
>> [...]
>
> It tries too but "heapify" uses the struct "BinaryHeap" that is 
> not safe at all.
> (either not annotated or @safe not applicable because of what 
> it uses in intern: @system stuff)
>
>> [...]
>
> No easy "good" way:
> 1. BinaryHeap is an old container
> 2. It would require to patch the standard library. So virtually 
> not available before weeks (but after a quick look it doesn't 
> seem possible)
>
> There's an easy "bad" way:
>
> import std.container.binaryheap;
> @safe // This makes things fail.
> unittest
> {
>     void foo() @trusted
>     {
> 	    import std.algorithm.comparison : equal;
> 	    int[] a = [4, 1, 3, 2, 16, 9, 10, 14, 8, 7];
> 	    auto h = heapify(a);
> 	    assert(h.equal([16, 14, 10, 9, 8, 7, 4, 3, 2, 1]));
>     }
> }
>
> but "bad", don't forget ;)
> It's a complete cheat to trust here.

Thanks for your quick answer! In this case I'll try to rewrite 
BinaryHeap. The bad way came to my mind too :). But I don't like 
it as does not really make things @safer.