Ada policy

[Robert Dewar]

Laurent GUERBY wrote:

> This kind of liberty is only available for compiler writers that are
> able to "bootstrap", and not for software in general, so no general
> conclusion should be taken there :).

I wouldn't go that far. A lot of big applications using gcc (gnat,
or g++ or gnu-c or ..) decide that it is fine to restrict their application
to being compilable only with gcc.

For example, it is definitely attractive to use nested functions in C
if you decide to rely on gnu-c. This can for example make it
considerably easier to write thread-safe C (since what otherwise
might be global variables can be uplevel task-specific stack
references).