tree 9040078f332eefe1e4c1d9345094bc68208a57b3
parent 2ee2f1ec57d9094643db60210c28b989f2e7da83
author Jason Evans <jasone@canonware.com> 1459038637 -0700
committer Jason Evans <jasone@canonware.com> 1460366142 -0700

Refactor/fix ph.

Refactor ph to support configurable comparison functions.  Use a cpp
macro code generation form equivalent to the rb macros so that pairing
heaps can be used for both run heaps and chunk heaps.

Remove per node parent pointers, and instead use leftmost siblings' prev
pointers to track parents.

Fix multi-pass sibling merging to iterate over intermediate results
using a FIFO, rather than a LIFO.  Use this fixed sibling merging
implementation for both merge phases of the auxiliary twopass algorithm
(first merging the aux list, then replacing the root with its merged
children).  This fixes both degenerate merge behavior and the potential
for deep recursion.

This regression was introduced by
6bafa6678fc36483e638f1c3a0a9bf79fb89bfc9 (Pairing heap).

This resolves #371.