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From: David Abrahams (dave_at_[hidden])
Date: 2002-11-16 08:18:28


In Boost.Python, I am going to start using custom deleters to enable
me to produce shared_ptr<T> from any Python object which contains a T,
while keeping the Python object alive. I can't believe I didn't think
of this earlier, and I want to thank Peter Dimov for putting me onto
the idea.

Each such shared_ptr<T> contains a pointer to the owning Python
object, whose identity is associated with that of the T object it
contains. When these shared_ptrs are converted back to Python, I
currently have to build a new Python object around a copy of the
shared_ptr<T>, so that now there are two Python objects using the same
C++ object's "guts". It would be very useful if I could introspect
about the deleter, and find out that it was using my custom deleter,
extract the Python object pointer, and simply return that instead of
building a new Python object.

Looking at the code, I can see a few ways to hack that functionality
in, but I wonder if we should think about making it part of the public
interface? After all, the deleter is part of the public interface for
shared_ptr creation...


                       David Abrahams
   dave_at_[hidden] *
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