[Boost-users] newbie's questions about multi_index

From: Guillaume Lazzara (glazzara_at_[hidden])
Date: 2007-04-01 16:28:59

Hi,

I'm currently using multi_index and I have few questions:

- I have a multi_index with composed keys, sometimes I need to get a
range of items, iterate over them and modify their key. How can I do
this properly?

sample code:

EquivSet::iterator tmp;
std::pair<EquivSet::iterator, EquivSet::iterator> es =
contains.equal_range(*it);
for (EquivSet::iterator it_equiv = es.first; it_equiv != es.second;)
  if (!X[it_equiv->id])
  {
    tmp = it_equiv++;
    contains.modify_key(tmp, update_equiv(nbEns));
  }
  else
    it_equiv++;

In this example, the second iterator in the pair, normaly used as end
iterator, can be changed and, sometimes, the loop iterates beyond the
latter.

- If I can choose between a std::set and a multi_index used as a set,
which one should I use?

Thank you very much for your answers!

-- 
Guillaume Lazzara
Epita CSI 2008