Re: [boost] [vault] ctor_shared_from_this()

From: Frank Mori Hess (fmhess_at_[hidden])
Date: 2007-12-23 20:57:35

On Sunday 23 December 2007 11:12, Robert Sitton wrote:
> I've had a few cases where my design required calling
> shared_from_this() in a constructor and destructor.  I made some
> modifications to enable_shared_from_this which I have posted here:
>
> http://www.boost-consulting.com/vault/index.php?order=rating&direction=1
>&directory=Memory
>
> There is a test function in a test file in the zip archive that will
> fail if you call shared_from_this() instead of my
> ctor_shared_from_this() method.

But it just creates a shared_ptr with a null deleter in the constructor.  I 
don't see how it adds anything over just using a raw pointer, since the 
shared_ptr in the constructor will have no relation to the external 
shared_ptr which will actually own the object after it is constructed.  To 
do that, you would need to something along the lines of storing a copy of 
the shared_ptr inside the object until it is passed over to an external 
shared_ptr that really owns the object.  Or, use a post-constructor and 
get the shared_ptr there, which is what I tried to support with 
deconstruct_ptr/postconstructible: 

http://www.comedi.org/projects/thread_safe_signals/libs/thread_safe_signals/doc/html/boost/deconstruct_ptr.html

-- 
Frank