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Subject: Re: [boost] Boost.Process 0.5 released
From: Boris Schaeling (boris_at_[hidden])
Date: 2012-08-19 06:12:18

On Sat, 18 Aug 2012 20:27:04 +0200, Klaim - Joël Lamotte
<mjklaim_at_[hidden]> wrote:

> [...]Making it non-copyable would force the user to use shared pointers
> to
> achieve the same, but it would then make it obvious that an instance of
> child is the unique representation of a child process, and that if you
> want
> to share it, like std::thread, you have to share references to it in a
> way
> or another, like with a shared_ptr.

Maybe the name child is a bit misleading. It should really be a PID
(POSIX) and process and thread handle (Windows) only. And as you can copy
PIDs and handles as much as you want (and no one has a problem with those
being copyable), child should work the same. From this point of view, I
think boost::noncopyable would be an overkill.

> [...]By the way, in this example:
> #if defined(BOOST_WINDOWS_API)
> typedef boost::asio::windows::stream_handle pipe_end;#elif
> defined(BOOST_POSIX_API)
> typedef boost::asio::posix::stream_descriptor pipe_end;#endif
> boost::asio::io_service io_service;
> pipe_end pend(io_service, p.source);
> Can't there be a utility function that would provide the right type
> depending on the target platform?

I wonder whether this should be done in Boost.Asio? But if I compare
windows::stream_handle or posix::stream_descriptor there are some slight
differences. Then we are at the core problem again we struggle with in
Boost.Process for several years: What do we do with differences between
platforms if we don't like #ifdefs? Either we support the minimum set of
cross-platform features or implement no-ops on those platforms a feature
is not supported on or invent a new high-level layer abstracting the
differences away?

> [...]If this library is proposed to the standard later, removing any
> macro use
> for the user would be mandatory anyway.

Thanks for the encouragement! I'd already be happy if we can get something
into Boost after six years. ;)


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