[C++-sig] Re: Enhanced shared_ptr support

[Brett Calcott]

This is very cool.
Thanks...

>
> A few days ago I checked in some changes to the way shared_ptrs get
> converted to Python.  A while back I had added a special shared_ptr
> deleter which caused all shared_ptr conversions from python to
> maintain the lifetime of the owning Python object, not of the C++
> object.  In other words, we'll have this:
>
>       shared_ptr<T>         T
>      +------+------+     +------+
>      |      |      |     |      |
>      |  *   |   *------->|      |
>      |  ||  |      |     |      |
>      +--||--+------+     +------+
>         ||                  /\
>         \/                  ||
>      +-----------------+    ||
>      |                 |    ||
>      | Python Object *======++
>      |                 |
>      +-----------------+
>
> The double lines represent ownership relationships.  Now, when such a
> shared_ptr is converted back to python, the owned Python object is
> returned, rather than a new Python object being built around the
> shared_ptr, sharing ownership of the T object with the Python object
> above.
>
> -Dave
>
> --
> Dave Abrahams
> Boost Consulting
> www.boost-consulting.com