Re: [boost] singleton_ptr

From: Peter Simons (simons_at_[hidden])
Date: 2005-07-18 10:55:08

Jason Hise writes:

 > singleton_ptr < Type > ptr;
 > ptr.create ( /*ctor params here*/ );
 > ptr.create ( /*ctor params here*/ );

What happens when two threads call create() at the same time?

 > I will have to look up call_once before I will be able to
 > compare it with my approach.

My guess is that you will need call_once() as part of your
implementation for it to be thread-safe (because of the
race-condition mentioned above).

 > Others have expressed (perhaps not publicly) that their
 > preferred method would be that secondary destructions are
 > simply no-ops, rather than being errors or asserting at all.
 > Such conflicting interests make it seem like a policy is
 > indeed necessary.

Well, having a policy mechanism won't hurt. I'm all for it. ;-)

Peter