Mathias Gaunard wrote:
Janek Kozicki wrote:
Is it possible to use those two together? I'm considering storing my polymorphic stuff into ptr_container but vector (or other standard containers) are not enough for my needs.
Using Boost.MultiIndex with Boost.PtrContainer would be great.
As far as I understand it, pointer containers are more efficient than containers of smart pointers because standard containers rely on copy semantics instead of move semantics (currently).
That is to some extend true, though we have seen some cloning smart-pointers posted here on the list that had pretty good efficiency (the one I'm thinking of was a copy-on-write pointer). But the differences are more than that. For example, wirh a move_ptr it's not possible to have containers (that guarantees to be) without nulls; the pointer containers can keep that invariant because they move the object and subsequently remove the pointer from the container. Moving from a standard like container would leave a null sitting there in the middle of the container.
But since we're inside of boost, couldn't multi index be smart enough to not do copying with smart pointers?
I guess it could. I use a move_ptr by Jonthan Turkanis internally in Boost.PtrContainer. -Thorsten