Re: [boost] [system] system_error first draft

From: Christopher Kohlhoff (chris_at_[hidden])
Date: 2006-06-26 09:54:54

Beman Dawes <bdawes_at_[hidden]> wrote:
> I'm very curious to hear if people think the newer names are
> an improvement over the TR2 versions.

What about maybe ditching the member functions sysno_value() and
errno_value() entirely and instead having additional free
function overloads:

  sysno_t to_sysno(error_code ec);
  errno_t to_errno(error_code ec);

And the only way to set an error code is by assignment:

  ec = 1234; // sysno
  ec = error_code(1234, from_errno);

Some quick notes on the implementation (sorry for the noise if
someone has already mentioned them):

- I notice that you only use strerror() on POSIX platforms. On
  some platforms this is not threadsafe, and strerror_r() needs
  to be used instead. From memory this function's behaviour can
  differ a bit between various platforms as well.

- The ::LocalFree() usage isn't exception safe.

See:

<http://boost.cvs.sourceforge.net/boost/boost/boost/asio/system_exception.hpp?revision=1.1&view=markup>

in the implementation of what() for an example.

Cheers,
Chris