Re: GCC 4.0 Ada.Containers Cursor danger.

["Matthew Heaney" <mheaney@on2.com>]

Dmitriy Anisimkov wrote:
>
> <<The checking of the cursors could take considerable size and
> performance. It is why i propose to have containers implementation
> without cursors. Who need a cursors would pay by size and
> performance.>>

A couple of points.  The ARG solicited proposals for a container API
over three years ago.  (Work on the design of the library began in
earnest at a workshop during the Ada-Europe 2002 meeting in Vienna, and
work on the library hasn't stopped since.)  If you had wanted a
container API sans cursors, then you should have submitted an API two
years ago.  It is pointless to be arguing for major changes to the
draft API on the eve of its standardization.

The other issue is that there is no cost in size or performance to have
cursors.  Implementations don't have to do anything special to
implement cursors.  Even without cursors, it's doubtful implementations
would change at all.

The only cost in size or performance is the overhead necessary to
detect dangling cursor references (and not, as you suggest above, to
merely provide cursors).