Benoit skrev:
OK, BOOST_FOREACH aside, iterating over a range returned as a pair of iterators can be painful and ugly:
I have encountered the same problem, but i am not sure why you would want to use anything but BOOST_FOREACH...
for (vertex_iterator pv,ve = xxx(pv,vertices(g)); pv != ve; ++pv) Moreover, in my opinion, the above construct seems a bit awkward to me. Modifying pv and pe at the same time, one as a function parameter, the other initialized with what the functions returns is a best very confusing. It's very clever, though, but again, why not use BOOST_FOREACH ?
Another idea might be to directly use a pair of iterators by creating a special structure for "duplicate pairs"...
for( duplicate_pair<vertex_iterator> vip( vertices( g ) ) ; vip.first != vip.second ; ++vip.first ) { //... }
I am not sure there's a real gain here though. Oh well. Can't blame me for trying ! :-)
FWIW, You can already today do for( boost::iterator_range<vertex_iterator> vip( vertices( g ) ) ; !vip.empty(); vip.advance_begin(1) ) -Thorsten