Joaquin,

many thanks for your detailed answer. I decided to handle this problem in a bit different manner. To split the entry class in 2, where the first one with field x contains all to x related tuple items as an indexed collection. That works fine and I can use boost::transform_iterator and boost::filter_iterator to efficiently access the content of the entry without copying the iterators into the vector.

Many thanks again,
Ovanes

On Tue, Mar 4, 2008 at 11:06 PM, Joaquin M Lopez Munoz <joaquin@tid.es> wrote:

>
>Ovanes Markarian <om_boost <at> keywallet.com> writes:
>

>[...]

>> class entry{
>> public:
>> field x;
>> field y;