Re: Ada Popularity: Comparison of Ada/Charles with C++ STL (and Perl)

[kevin.cline@gmail.com (Kevin Cline)]

"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> wrote in message news:<1g2d9xmnita9f.5ecju0eftkqw$.dlg@40tude.net>...
> On 27 Sep 2004 07:31:44 -0700, Kevin Cline wrote:
> 
> > Matthew Heaney <matthewjheaney@earthlink.net> wrote in message news:<uekkpt07s.fsf@earthlink.net>...
> >> kevin.cline@gmail.com (Kevin Cline) writes:
> >> 
> >>> One of the most frustrating things I found in Ada programming was the
> >>> inability to make user-defined types work like the built-in types. 
> >>> Given
> >>> 
> >>>   A: array (1..10) of integer;
> >>> 
> >>> then the expression A(5) is a modifiable reference to the fifth
> >>> element of A.
> >>> 
> >>> After experience with C++ it was amazingly frustrating to learn that
> >>> there was no way I could define My_Container so that I could write:
> >>> 
> >>>   C: My_Container ;
> >>> 
> >>>   C(5) := 7;
> >> 
> >> Indeed, you cannot do this.  In AI-302 (and in Ada.Strings.*), you have to say:
> >> 
> >>    Replace_Element (C, Index => 5, By => 7);
> > 
> > I think this was a major error in the language design.
> 
> It was not an error, in the sense that no irreparable damage was done. It
> seems that the issue was just put aside for better times. Ada has a rich
> infrastructure supporting array types and their index types. So to reshape
> Ada's arrays out of abstract "array interfaces" one need to take all that
> presently hard-wired infrastructure with. Note that C++ does not solve the
> problem, because it has no arrays. So it allows you to define [] and leaves
> you alone with that. It is not the Ada's way (TM).

C++ solves the problem very nicely, it just wasn't solved once and for
all by the language designer or by the standard committee.  It's not
necessary for C++ to have a sophisticated built-in array class because
it is relatively easy to build any sort of array you like.  So we have
std::vector and boost::array, and if you need a sparse array or any
other sort you can build that too and they will all work with the
standard algorithms and you can switch out one for another with little
effort.