File Descriptor - Auto-close Doesn't Properly Handle Errors

[m-renaud]

If auto_close is set for the file descriptor, ::close() is invoked in the destructor but not all errors can be properly handled.

EBADF

Occurs when fd isn't a valid file descriptor.

Possible solution is to ignore this error as the file descriptor may have already been closed. Nothing should be wrong with redundant closing.

EIO

An I/O error has occurred.

Not sure exactly how you would go about handling this error.

[m-renaud]

Since it is poor design to write destructors that throw, the auto close shall be removed from file_descriptor. In order to close a file_descriptor, the close() member function must be invoked so that proper error handling can be done.

Note: This change was made in the exception branch for now and will eventually be merged back into master when a fully robust implementation is complete.