Re: Overlay allowability

[Ted Dennison <dennison@telepath.com>]

In article <39184D91.13BA15B4@Raytheon.com>,
  "Samuel T. Harris" <samuel_t_harris@Raytheon.com> wrote:

> problems across compiler implementations. It is rare that
> such interfacing code deals with unconstrainted arrays
> or polymorphic variant records. Usually just run-of-the-mill
> scalars, static records, and constrainted arrays.

The typical use I've seen of it (UC-ing addresses into object pointers)
is in converting random data objects into arays of bytes. Since the base
type for one side is typically an unconstrained array of bytes, I think
this is quite likely to be an issue.

Usually this is done to convert some nice user data structure into
something an entity outside of Ada (such as an OS call) can deal with.
Just about any other use is going to be a hack around a badly-chosen
type. Thus the Right Thing would be to redesign the type.

--
T.E.D.

http://www.telepath.com/~dennison/Ted/TED.html


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