Re: Efficiency of code generated by Ada compilers

[Florian Weimer <fw@deneb.enyo.de>]

* Elias Salom�o Helou Neto:

> I would like to know how does code generated by Ada compilers compare
> to those generated by C++. I use C++ for numerical software
> implementation, but I am trying to find alternatives. One thing,
> however, I cannot trade for convenience is efficiency. Will Ada
> compiled code possibly be as efficient as that generated by C++
> compilers?

For Ada 83 features except tasking, performance will be very similar.

> Also, I do need to have something similar to C++ "templated
> metaprogramming" techniques. In particular, C++0x will introduce
> variadic templates, which will allow us to write templates that will
> generate efficient, type-safe, variable-argument functions. Is there
> anything like that in Ada?

You could try writing a code generator, possibly using ASIS.  Whether
this is practical depends on the task at hand.  A code generator is
typically not more difficult to build than a good template
meta-programming library (which is a code generator, too, but has to
be written in a rather bizarre way).

> If any of the above questions is to be negatively answered, I ask: why
> does Ada even exist?

It's older than (modern) C++, so there is tons of software that uses
it, and it has a relatively safe subset which is difficult to leave.

> And further, is there any language which is _truly_ better
> (regarding code maintainability, readability and developing ease)
> than C++ and as overhead-free as it?

D is often mentioned in this context.

For many tasks, it's difficult to do significantly better than C++
without garbage collection, so the question is whether you can afford
that.  (Few Ada compilers support garbage collection, though.)