Re: [Boost-users] BGL: d_ary_heap_indirect duplicated values

Subject: Re: [Boost-users] BGL: d_ary_heap_indirect duplicated values
From: David Doria (daviddoria_at_[hidden])
Date: 2012-09-05 10:42:17

> I looked over and tried your code; there are two issues that I see:
>
> 1. The index_in_heap_map is initialized to 0, rather than (size_t)(-1) (the
> 4294967295 you are seeing after vertices are popped).  It looks like that
> isn't a problem when an unconditional push is used to add to the queue, but
> push_or_update does check whether the element is already in the queue.

Where do you see this being initialized to zero? (i.e. where should I
changed it to be initialized to -1?). I thought that this map was
being set explicitly in the push() function anyway (so why does the
initialization matter)?

> 2. It looks like copying d_ary_heap_indirect objects doesn't work correctly
> (it should probably be a shallow copy, while here it is trying to do a mix
> of both).  Thus, your output routine is removing elements from a copy of the
> heap data (since the heap structure itself is deep-copied) while marking
> them "not present" in the original index_in_heap_map (since that is
> shallow-copied).  I'll just make it noncopyable for now, and it will likely
> stay that way unless someone has a compelling need for something else.

Ah, I see that now. How else would I inspect the current ordering? I
guess just pop them all off into another container and then push them
all back in?

David