constant record components in Ada

[Alexander V. Konstantinou <akonstan@sutton.cs.columbia.edu>]

I am trying to obtain in Ada (95) the same functionality of the C++ struct
declaration :

	struct map_pair {
		const Key_Type first;
		Value_Type second;
	}

The idea is to provide a record in which the key value is constant, and the
value type is mutable.  The Ada books I have looked at suggest using
discriminants.  Unfortunately, discriminants have to be either discrete or
access types.  In my case Key_Type is a generic parameter and restricting it
to be a discrete type is too restrictive.  On the other hand, making the
discriminant a pointer is in my view an ugly solution since it keeps that
extra pointer around.

Any ideas on how to tackle this ?

Alexander V. Konstantinou
-- 
Alexander V. Konstantinou              http://www.cs.columbia.edu/~akonstan/
akonstan@cs.columbia.edu               akonstan@acm.org