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From: jls@yoda.Rational.COM (Jim Showalter)
Newsgroups: comp.lang.ada
Subject: Re: ADA Compiling Query
Keywords: Ada
Message-ID: <jls.666659373@yoda>
Date: 15 Feb 91 23:09:33 GMT
References: <5572@baird.cs.strath.ac.uk> <1991Feb13.211643.25777@rti.rti.org> <2725@sparko.gwu.edu>
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List-Id: <comp.lang.ada>

There is an unsafe aspect of passing access types as IN parameters in Ada
that is, sad to say, handled rather better in C++.

In Ada, you can pass an access type to a function as an IN:

	type Some_Foo...

        type Pointer is access Some_Foo;

        function Some_Bar (Some_Param : in Pointer)...

And then, inside the function, dereference the pointer and modify the
pointed-to construct.

In C++, you can declare not only the pointer constant but the pointed
to construct constant as well. This allows passing by reference in a
read-only manner, which is NOT possible in Ada at present.