A question to the "access-type lifetime rule"

[Bernd Rinn <bernd@hamilton.physik.uni-konstanz.de>]

Hi,

I am new to Ada and I am looking for an elegant way to get around a
restriction posed by the "access-type lifetime rule" for
access-to-subprogram types. First of all: does anyone know, why the
access-type lifetime matters and not the access-variable lifetime? (This
should prevent dangling pointers as well, I guess.)

I want to write an numerical integration function, that is defined in a
separate package as

type Integrand_Type is access function ( X : Long_Float ) return
Long_Float;
function Integrate(Integrand : Integrand_Type; Lower_Bound, Upper_Bound
: Long_Float) return Long_Float;

Now I would like to call this from a main procedure and pass an access
attribute of a nested function of the main procedure as `Integrand'. Is
there a way to reach this? (Unchecked_Access is not an allowed attribute
for subprograms and I do not want to generate a package of it's own for
the integrand function.)

Thank you for your help.

Best regards,

Bernd

--
Bernd Rinn
Fakult�t f�r Physik
Universit�t Konstanz

Tel. 07531/88-3812,
e-mail: Bernd.Rinn@uni-konstanz.de
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