Re: array conversion - how to do?

[Geert Bosch <geert@gonzo.sun3.iaf.nl>]

Robert I. Eachus <eachus@spectre.mitre.org> wrote:
       I used to worry about the fact that doing these conversions
   efficiently meant instantiating Unchecked_Conversion, but I
   eventually came around to the understanding that that is exactly
   what is happening here.

At first I had expected that the conversion would be allowed if the
elements of the source and target array had the same base type. Then
the compiler could add the standard checks for subtype conversion and
eliminate them in cases where the checks are known to succeed, like
in my example for conversion from ASCII_String to String.

The drawback of my generic Array_Conversion is that it is too powerful
in that it can convert an array of A to an array of B as long as B is
a new A. I would like to only allow conversion when A and B are subtype
compatible. Anyway, the point was to avoid copying as happens in the
loop approach, but at least GNAT doesn't seem to do that yet.

Hopefully this will improve with time.

Regards,
   Geert