2008/12/7 vicente.botet <vicente.botet@wanadoo.fr>:

Hi,

I have created a new wiki page containing some of the libraries under construction for Boost. You can access this page from the Boost Trac wiki https://svn.boost.org/trac/boost/wiki > Projects > Libraries Under Construction or directly https://svn.boost.org/trac/boost/wiki/LibrariesUnderConstruction

HTH, Vicente

Thank you, Vicente, for creating this list and putting my lib Boost.ITL (Interval Template Library) on the list. Browsing through the list I spotted *DenseSet* on the Libraries Wish List. "Implementation of dense set of integers using intervals" I think that such a dense set is already contained in itl::interval_set. Intervals themselves are dense sets but they are incomplete for most of the fundamental set operations. While intersection interval& operator *= (interval& i1, const interval& i2) always yields a (dense) interval, set union (+=) or set difference (-=) do in general not yield an interval. They result in a set of intervals, the union of which is again a set (of elements). The itl's interval_set implements exactly this completion of incomplete operations on intervals. {[1,3]} + [2,4] -> {[1,4]} //dense {[1,3]} + [5,5] -> {[1,3],[5,5]} //not dense {[1,3],[5,5]} + [4,4] -> {[1,5]} // dense again itl::interval_set is *implemented* as a set of intervals but it's semantics is the union of those intervals, which is a set of elements. An itl::interval_set is in a minimal representation. So the criterion of density can always be tested by: interval_set<int> iset; iset += interval<int>::closed(1,3); ... // more operations bool is_dense = iset.size()<=1; // a nonempty interval_set is dense, iff it's size is 1. I wonder whether you have more properties of DenseSet in mind that might go beyond the functionality of itl's interval_sets. May be those features could be integrated into the itl. Cheers Joachim