Re: Access keyword

["Randy Brukardt" <randy@rrsoftware.com>]

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"S�bastien" <seb.morand@gmail.com> wrote in message
news:fv79c8$lik$1@registered.motzarella.org...

> I'd like to know if there is performance issue using the access keyword?

You are actually talking about "access parameters" (the access keyword
occurs in many contexts and the answer is likely to be different in many of
them - it is best to be precise). Yes, it is generally going to be slower,
for the reasons Adam mentioned. It would be possible for a compiler to
optimize away that extra overhead, but it would probably only be practical
if all of the calls and bodies are compiled together.

For this reason and others I recommend that access parameters only be used
in cases where a conventional Ada design would be more complicated. That
almost never happens.

You often need access *types* to implement the bodies of decent
abstractions, but it is rare that they need to be exposed in the interface
in any way.

Anonymous access types (a superset of access parameters) mainly exist in Ada
to make it easier for C++ and Java programmers to move their rotten designs
to Ada. Bah humbug.

                           Randy.