Re: why can't we declare unconstrained objects ?

[Martin Dowie <martin.dowie@btopenworld.com>]

Michael Mounteney wrote:
> Is there a simple way in Ada of simulating C/C++ unions ?  It seems to
> me that this is gratuitously prevented, that is, it can be done with
> safety, by extending an existing run-time check, but it is in fact
> prevented by the compiler.
> 
> Hopefully the following commented source will illustrate my point.
> 
> with Ada.text_IO;
> 
> procedure unconstrained is
> 
> 	-- Very simple discriminated type
> 	type thing (what : Boolean) is

Simply add a default to the discriminant and you can change it all you 
want at run-time (e.g. "what : Boolean := Boolean'First").

Cheers

-- Martin