Inherited from basic_file.
Release ownership of the underlying native file.
native_handle_type release( asio::error_code & ec);
This function causes all outstanding asynchronous read and write operations
to finish immediately, and the handlers for cancelled operations will
be passed the
asio::error::operation_aborted error. Ownership
of the native file is then transferred to the caller.
Set to indicate what error occurred, if any.
This function is unsupported on Windows versions prior to Windows 8.1,
and will fail with
on these platforms.