Boost::binomial_heap - decrease bug

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Hello. I was messing around with boost::binomial_heap today and I think I may have found a bug. Essentially, when I construct a min-heap with binomial_heap, insert elements, and decrease an element to become the smallest, it's not at the top.

I've attached a small enough reproducer. Here's the result on execution: ​http://coliru.stacked-crooked.com/a/28fe3afdedda9d76

As you may see, the output should be:

-1 1 1 2 3 4

Indeed, this is the output in the case of boost::fibonacci_heap and boost::pairing_heap. However, in the case of boost::binomial_heap, the output is:

1 -1 1 2 3 4

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Reproducer