Re: Which is best way to store objects?

From:
James Kanze <james.kanze@gmail.com>
Newsgroups:
comp.lang.c++
Date:
Mon, 4 Jan 2010 15:22:37 -0800 (PST)
Message-ID:
<06699f21-cbb4-4af5-8732-b82c7f764801@p8g2000yqb.googlegroups.com>
On Jan 3, 3:41 pm, Jeff Flinn <TriumphSprint2...@hotmail.com> wrote:

James Kanze wrote:

On Jan 2, 10:45 pm, "Leigh Johnston" <le...@i42.co.uk> wrote:

Which makes one ask questions. Since pointers (raw or
otherwise) have different semantics than using the objects
themselves. You simply can't replace one with the other.


If you wanted a container of polymorphic objects (i.e.
std::vector<base*>) then shared_ptr is ideal.


That's very debatable. Most polymorphic objects are entity
objects, for which the semantics of shared_ptr are not
appropriate.


Why not? Can you expound on that statement.


The obvious answer is, because it doesn't have the desired
semantics. What are the semantics of shared_ptr? What are you
using your pointers for?

At least in the applications I've seen, most pointers are for
navigation, and most dynamic objects have deterministic
lifetimes. Boost::shared_ptr does not have the semantics of a
pointer used for navigation, and it prevents proper
deterministic lifetime.

--
James Kanze

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