On Tue, Sep 22, 2015 at 5:26 PM, Daniel Cheng via cfe-commits < cfe-commits@lists.llvm.org> wrote:
> dcheng added a comment. > > In http://reviews.llvm.org/D13080#251324, @dblaikie wrote: > > > I'd still be curious to see a stronger justification from the standard > > about this. > > > > I know you mentioned/quoted the definition of ~unique_ptr in the > standard - > > but I'm not sure that is meant to imply observable behavior during > > destruction (though I could be wrong). Is there anything in the standard > > about accessing objects while their dtors are executing? > > > From 3.8.5 [basic.life]: > Before the lifetime of an object has started but after the storage which > the object will occupy has been > allocated or, after the lifetime of an object has ended and before the > storage which the object occupied is > reused or released, any pointer that refers to the storage location where > the object will be or was located > may be used but only in limited ways. For an object under construction or > destruction, see 12.7. > > From 12.7.1 [class.dtor]: > For an object with a non-trivial destructor, referring to any non-static > member or base class of the object after the destructor finishes execution > results in undefined behavior. > > So I believe the standard permits object access while the dtor is still > executing. > Thanks for the wording - seems plausible. My other hesitation here is: if the object being destroyed needs to use itself through the pointer in the unique_ptr, isn't it already fragile/broken? If the unique_ptr was reset or set to null, etc, before destruction happened it would fail in the same way it is failing now? So it's not safe to be held by a unique_ptr, really... > > > http://reviews.llvm.org/D13080 > > > > _______________________________________________ > cfe-commits mailing list > cfe-commits@lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits >
_______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
