Re: [Boost-users] [multi_key] problems using modify_key with a composite_key index

Jeffrey Holle wrote:

Joaquín Mª López Muñoz wrote:

...

So, instead of using modify_key resort to plain modify instead:

c.get<1>().modify(c.get<1>().find(make_tuple(y,UINT_MAX)),&ll::_1->*&entry::m_x=startIter2->m_x);

...

Is your problem solved now?

This solved my compilation problem, but I ended up with an app than wants to runs forever.

To be clear, I'm including my entire function. What it is supposed to do is reorder the x values of the composite_key index of the multi_index container based on the ordering of a vector<float> container. It is a swap_sort algorithm because its the only way that I've imagined how to do this. A better solution would definitely be entertained.

void sortByBaryCenterValue(Positioner& p, BaryCenterVals& bcv,size_t y) { Positioner::XYIterator iter,iter_end; tie(iter,iter_end)=p.getXYIndex().equal_range(make_tuple(y)); for (size_t nStartIndex=0;nStartIndexm_x; advance(smallestIter,nSmallestIndex); size_t x2=smallestIter->m_x;

//

p.getXYIndex().modify(p.getXYIndex().find(make_tuple(y,x1)),&ll::_1->*&Positioner::entry::m_x=UINT_MAX); p.getXYIndex().modify(p.getXYIndex().find(make_tuple(y,x2)),&ll::_1->*&Positioner::entry::m_x=x1);

p.getXYIndex().modify(p.getXYIndex().find(make_tuple(y,UINT_MAX)),&ll::_1->*&Positioner::entry::m_x=x2);

} }

If I uncomment the middle line of the sort attempt, the application runs forever.

Do you know what is wrong? Thanks in advance.

Found my problem. A sort-swap algorithm has a self-swap "feature". When x1 and x2 are the same, the above function will lock up (when the offending line is uncommented. The solution is to put the swap operation within a conditional clause.