Re: Teaching new tricks to an old dog (C++ -->Ada)

[Marius Amado Alves <amado.alves@netcabo.pt>]

> Template metaprogramming is a very useful field.

Yes. Generic programming. This is a worth discussing issue in a an Ada 
v.s C++ battle.

(Forget libraries being or not being implemented in the language, 
forget inlining, these are trivial issues. Of course Ada.Containers is 
written in Ada, and of course the crucial operations are inlined.)

Now, generics.

We should keep in mind that the STL begun life as an Ada library.  See 
the famous Stepanov interview at 
http://www.sgi.com/tech/stl/drdobbs-interview.html  His contact with 
Ada generics was crucial for the development of C++ templates and the 
STL.  He move to C/C++ for career reasons and basically he (consulting 
with Stroutstrup) created C++ templates because he needed generics in 
C++ to do there what he had done in Ada!

Of course along the way C++ generics was made very different from 
Ada's. In general more powerful.  Less safe?  I don't know.

Two limitations of Ada 95 generics are: a generic cannot be 
instantiated inside itself; the generic formal types must match, not 
just the actuals.  I think Ada 2005 did not change this directly, but 
she has a couple of new tricks e.g. interfaces that might help 
circumvent it.