Main subprogram at library level (was: library level required or not?)

[Jeffrey Carter <spam@spam.com>]

Randy Brukardt wrote:

> *Types* derived from Controlled have to be at library-level.

I have just had an idea. Suppose we had a standard pragma that declared 
that a library-level subprogram was a main subprogram. The subprogram 
could then only be a main subprogram and could not be called by itself 
or another subprogram, only by the environment task.

The declarative region of such a subprogram would then be considered to 
be at the library level, allowing controlled types to be declared there.

This would make Ada a little easier for newcomers without impacting 
existing code, which would not have the pragma and hence would not allow 
controlled types there.

Has anything like this been proposed before? Any thoughts as to whether 
it is likely to fly if submitted as an AI?

-- 
Jeff Carter
"Your mother was a hamster and your father smelt of elderberries."
Monty Python & the Holy Grail
06