[Bug libstdc++/53263] priority_queue is very slow if -D_GLIBCXX_DEBUG is used

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53263

--- Comment #4 from Paolo Carlini <paolo.carlini at oracle dot com> 2012-05-07 12:54:36 UTC ---
I see, I see.

First, I notice that we don't have a specific debug/ version of it, thus you
are using the normal version + debug-mode std::vector and std::????_heap
algorithms as implementation details. Likely the latter are the problem, I
think we already noticed somewhere that std::push_heap & company check a lot,
check at every step that a proper heap is passed, but I don't remember the
outcome of that discussion.