On Tue, Nov 19, 2002 at 10:35:00AM -0500, David Abrahams wrote: > > On Tuesday 19 November 2002 07:11, Herve Bronnimann wrote: > >> Dave, Jeremy: one iterator adaptor I needed often (and once again today) > >> is the projection on the first or second member of a pair. I could make > >> it using projection_iterator<> and select1st, except that select1st is > >> an std extension from SGI. I haven't found any other out-of-the-box way > >> to do this, did I miss something? > > > > Not as far as I can see. > > Can't you just use make_projection_iterator with bind(&pair<X,Y>::first) ?
Would work fine for boost::compressed_pair, but not for std::pair, IIUC. In one, first is a member function, but in the other it's just a public data member. Even assuming it works, would it inline the access to first properly? Just wondering. I like Thomas' suggestion about tuples. If it could be made to work for tuples AND std::pairs, it would get my vote. I'll think about it. Meanwhile, std::pair is pretty special among tuples due to its relation to std::map and other parts of the standard. But looking forward, tuples might become just as important... point taken. Thanks for the replies, -- Herve' _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
