"Howard Hinnant" <[EMAIL PROTECTED]> wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > 1. Arrays of polymorphic objects don't work. > > Right. But to me that just means you don't want to have the member > template converting constructors/assignment in your array version of > the smart pointer (as shown in boost::shared_ptr/shared_array, and the > move_ptr example at > http://home.twcny.rr.com/hinnant/Utilities/move_ptr). > > > 2. If I wanna arrays of monomorphic objects I can use std::vector. > > True. > > > 3. If I wanna arrays of monomorphic objects and std::vector's > > performance > > is unsatisfactory to me, > > Naw, couldn't happen! ;-) > > > I can use the typed buffers > > (http://www.moderncppdesign.com/publications/cuj-08-2001.html, > > http://www.moderncppdesign.com/publications/cuj-10-2001.html, > > http://www.moderncppdesign.com/publications/cuj-12-2001.html) that are > > present in the up-and-coming YASLI. > > Up-and-coming? I was just getting used to "legendary"! :-)
Be afraid. Be very afraid. :o) > > 4. So there's no reason I'd ever wanna have smart pointers to arrays. > > I agree that vector (or vector-like substitutes) are preferred over > smart_ptr<T[]> in most circumstances. But there are times when > ownership of the array needs to be transferred or shared. In those > instances, vector is not a good fit. smart_ptr<vector<T> > is a > possibility, but this is typically inferior both in performance, and in > client level syntax (e.g. (*p)[i] instead of p[i]). When designing an amenity, it is important to figure out how the alternatives work for its target audience. For the limited audience that (1) needs a smart pointer to an array and (2) is unhappy with vector's performance, I'd say it's ok to just advice using a SmartPtr configured with an array deleter and have them write get_impl(sp)[45] instead of sp[45]. The super-performance-critical code portions of an app are not that large and much uglier for different reasons anyway :o). Andrei _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
