Re: Extensions in generic bodies - Language Laywer question

[eachus@spectre.mitre.org (Robert I. Eachus)]

In article <6vijho$qps$1@nnrp1.dejanews.com> dennison@telepath.com writes:

  > Here's one for the langauge Laywers. 3.9.1(4) says: "A type extension shall
  > not be declared in a generic body if the parent type is declared
  > outside that body."

  Yes, it has to do with dispatch tables.  The same problem occurs
with non-generic bodies, but other rules ensure that the problem cases
can never occur.

  > Does that also go for instantiating generics that *cause* a type
  > extension? My compiler seems to think so.

  Yes.

  > My situation: I'm trying to create a generic object. Internally
  > (In the body) I want to keep a queue of these objects...

  In this case, you should be able to declare the type in the private
part, and I remember that as the reason for keeping the rule simple.
In any case that can be made to work, the type declaration can be
moved to (the private part of) the generic spec.  This may, as in the
current case, also require moving with clauses.  (In pathological
cases, you have to move the declaration to a new child unit.)
--

					Robert I. Eachus

with Standard_Disclaimer;
use  Standard_Disclaimer;
function Message (Text: in Clever_Ideas) return Better_Ideas is...