[Boost-users] [heap] How to orderly traverse a priority queue and update a given element?

Subject: [Boost-users] [heap] How to orderly traverse a priority queue and update a given element?
From: Francisco Lopes (francisco.mailing.lists_at_[hidden])
Date: 2013-02-26 21:59:08

I'm looking for a good data structure that can *maintain* its elements
sorted. Currently I'm trying
Boost.Heap<http://www.boost.org/doc/libs/1_53_0/doc/html/heap.html>
.

I frequently need to orderly traverse the data structure, find a element
based on some property and update its priority when it matches. Boost.Heap
priority queues provide ordered and non-ordered iterators. Element updates
occurs through a element handle, a handle can be obtained from a ordinary
non-ordered iterator, but not directly from a ordered one as in the
following example:

#include <iostream>#include <algorithm>#include <boost/heap/fibonacci_heap.hpp>
using namespace boost::heap;
int main(){
    fibonacci_heap<int> fib_heap;

    fib_heap.push(1);
    fib_heap.push(2);
    fib_heap.push(3);

    for(auto i = fib_heap.ordered_begin(); i != fib_heap.ordered_end(); ++i)
    {
        auto h = fibonacci_heap<int>::s_handle_from_iterator(i);
        if(*h == 3)
        {
            fib_heap.increase(h, *h + 2);
            break;
        }
    }

    std::for_each(fib_heap.ordered_begin(), fib_heap.ordered_end(),
    [](const int &e)
    {
        std::cout << e << std::endl;
    });}

How can I orderly traverse the queue and update an element in the traversal?

Note that I leave traversal after the update.

(Suggestions of alternative libraries for such purpose are welcome)