Re: [boost] intrusive pointer, rationale for preferring shared_ptr instead.

From: Larry Evans (cppljevans_at_[hidden])
Date: 2006-04-10 13:11:54

On 04/06/2006 12:50 AM, Ulrich Eckhardt wrote:
> http://boost.org/libs/smart_ptr/intrusive_ptr.html says:
> "As a general rule, if it isn't obvious whether intrusive_ptr better 
> fits your needs than shared_ptr, try a shared_ptr-based design first."
[snip]
> Another related thing is why is there no complementary class to add a 
> refcounter to an object? Something like
> 
> template<typename ObjectType>
> struct refcount
[snip]
overhead_referent_vals here:

   http://tinyurl.com/k9jhr

does this, but with multiple inheritance instead of single.  It's
designed to be used with auto_overhead ( located in the same
directory ), which assures the pointer used in a smart_ptr points
into the heap.

A closely related discussion is here:

   http://archives.free.net.ph/message/20060331.100537.108c5fab.en.html

However the OP of that thread was just concerned ( AFAICT ) with the 
thread safety of creating the pointee, but auto_overhead is only
concerned with assuring that the argument to the smart_ptr CTOR must be
(as enforced by the compiler) from the heap.

I have plans to eventually add a source/sink policy to the
policy_ptr in the sandbox as proposed in may2005 (but didn't
generate much interest).  The sketchy proposal is here:

   http://archives.free.net.ph/message/20050511.215426.101ccded.en.html