From: Philippe A. Bouchard (philippeb_at_[hidden])
Date: 2002-09-02 21:10:05
Beman Dawes wrote:
[...]
> Greg Colvin's original shared_ptr design, as later extended by Greg and
> Peter Dimov, with help from Darin Adler and other Boosters, has proved to
> be far more versatile than anyone could have imagined when it was first
> proposed ten years ago, particularly when teamed with the other Boost
> smart
> pointers. But policy-based smart pointers may be a better choice for
> those who feel they absolutely must have 100% control over every detail of
> implementation.
I do not know yet the best policy to add. Maybe someone could help. I am
more oriented towards the garbage collector and here is what I am thinking:
Regular garbage collectors do not have a clue when exactly the object
should be destroyed. This is not good news for QT widgets, for example.
Maybe we could mix rc & gc advantages... to determine exactly when the
object's life is terminated with reference counts followed by destruction &
deallocation of the object using some type traits at a given time.
For example:
struct KeepAliveWANServers
{
... // Really slow constructor & destructor
};
struct KeepAliveLANServers
{
... // Relatively slow constructor & destructor
};
template <>
struct tree_traits<KeepAliveWANServers>
{
typedef simple_tree type;
typedef process_end destruction_mark;
};
template <>
struct tree_traits<KeepAliveLANServers>
{
typedef simple_tree type;
typedef thread_end destruction_mark;
};
template <>
struct tree_traits<int>
{
typedef simple_tree type;
typedef ref_end destruction_mark;
};
Integers shall be destroyed immediately, KeepAliveLANServers at the end of
the thread and KeepAliveWANServers at the end of the process.
We could add swap options, etc.
Philippe A. Bouchard