Re: friend classes in ada95 (long)

[Brian Rogoff <bpr@shell5.ba.best.com>]

On 24 Apr 2000, Hyman Rosen wrote:
> Brian Rogoff <bpr@shell5.ba.best.com> writes:
> > It seems that I ruffled your feathers by using that word in the context of 
> > your favorite language. Sorry. I actually liked the signature extension of 
> > C++. I'd love to see such a feature grafted onto Ada.
> 
> Sorry about that. My antennae sometimes get a little hyperextended in
> c.l.a. 

You'll probably have to develop a thicker skin, or tougher antennae,  
because this is com.lang.ada after all. I'm similarly annoyed by the 
gratuitous C++ slamming, even though I prefer Ada to C++ for most tasks, 
but that's the nature of comp.lang.*

> But as to signatures, I don't much care for them. It seems to
> me that they are there to take advantage of accidents in function
> naming, whereas interfaces are part of a design.

Is that from actual use, or just reading and inference? I don't have any 
real data myself, I just read about GNU C++ signatures. I did use Sather 
for a while, which also had a powerful signature-like mechanism that 
permitted the addition of signatures (types in Sather parlance) above 
an existing class. This feature was mainly used to define type bounds in 
generic classes. Since C++ doesn't have constrained parametric
polymorphism (yes, I know how to simulate it inelegantly in C++) this
isn't as important there. 

The real revolutionary aspect of standard C++ which I wish Ada would copy
is automatic generic/template instantiation. I think the modification to
Ada (read "An Ada like language") would be better off omitting the full
power of templates to do compile time calculations, and therefore omitting 
"template metaprogramming", but would still enhance Ada's abilities in a 
number of interesting ways. 

-- Brian