Re: C++, Ada, ...

From	Niklas Holsti <niklas.holsti@tidorum.invalid>
Newsgroups	comp.arch.embedded
Subject	Re: C++, Ada, ...
Date	2021-04-18 18:48 +0300
Organization	Tidorum Ltd
Message-ID	<ie32luFlvghU1@mid.individual.net> (permalink)
References	<s5f01b$4j3$1@dont-email.me> <s5f3c1$s06$1@dont-email.me> <AaGeI.148580$qHh9.147135@fx18.ams4> <s5h32f$edv$1@dont-email.me>

Show all headers | View raw

On 2021-04-18 13:53, David Brown wrote:
> On 17/04/2021 20:55, Tom Gardner wrote:
>> On 17/04/21 17:45, David Brown wrote:
>>> And most of
>>> the advantages of Ada (such as better typing) can be achieved in C++
>>> with less effort, and at the same time C++ can give additional safety on
>>> resources that is harder to get on Ada.
>>
>> Interesting. Could you give a quick outline of that?
>>
> 
> Which part?
> 
> My understanding of Ada classes is that, like Pascal classes, you need
> to explicitly construct and destruct objects.  This gives far greater
> scope for programmers to get things wrong than when they are handled
> automatically by the language.

If you mean automatic allocation and deallocation of storage, Ada lets 
you define types that have an "initializer" that is called 
automatically, and can allocate memory if it needs to, and a "finalizer" 
that is automatically called when leaving the scope of the object in 
question. The finalizer does have to explicitly deallocate any 
explicitly allocated and owned resources, and it may have to use 
reference counting for that, for complex data structures.

AUI that also holds for C++, although I believe recent C++ standards may 
have simplified the definition and use of reference-counted data structures.

> On the other hand, some of Ada's type mechanisms make it a lot easier to
> make new types with similar properties while remaining distinct (such as
> subranges of integer types).  You can do that in C++, but someone needs
> to make the effort to make the appropriate class templates.  Thus these
> are more often used in Ada coding than in C++ coding.

(That relative ease in Ada was the point of my other response -- more to 
come on that.)

> On the third hand (three hands are always useful for programming), the
> wordy nature of type conversions in Ada mean programmers would be
> tempted to take shortcuts and skip these extra types.

Huh? A normal conversion in C is written "(newtype)expression", the same 
in Ada is written "newtype(expression)". Exactly the same number of 
characters, only the placement of the () is different. The C form might 
even require an extra set of parentheses around it, to demarcate the 
expression to be converted from any containing expression.

Of course, in C you have implicit conversions between all kinds of 
numerical types, often leading to a whole lot of errors... not only 
apples+oranges, but also truncation or other miscomputation.

Thread

C++, Ada, ... pozz <pozzugno@gmail.com> - 2021-04-17 17:48 +0200
  Re: C++, Ada, ... David Brown <david.brown@hesbynett.no> - 2021-04-17 18:45 +0200
    Re: C++, Ada, ... Tom Gardner <spamjunk@blueyonder.co.uk> - 2021-04-17 19:55 +0100
      Re: C++, Ada, ... David Brown <david.brown@hesbynett.no> - 2021-04-18 12:53 +0200
        Re: C++, Ada, ... Niklas Holsti <niklas.holsti@tidorum.invalid> - 2021-04-18 18:48 +0300
          Re: C++, Ada, ... David Brown <david.brown@hesbynett.no> - 2021-04-18 18:59 +0200
            Re: C++, Ada, ... Niklas Holsti <niklas.holsti@tidorum.invalid> - 2021-04-19 13:51 +0300
              Re: C++, Ada, ... David Brown <david.brown@hesbynett.no> - 2021-04-19 14:22 +0200
                Re: C++, Ada, ... Niklas Holsti <niklas.holsti@tidorum.invalid> - 2021-04-19 19:16 +0300
                Re: C++, Ada, ... David Brown <david.brown@hesbynett.no> - 2021-04-19 22:19 +0200
                Re: C++, Ada, ... Niklas Holsti <niklas.holsti@tidorum.invalid> - 2021-04-20 01:03 +0300
                Re: C++, Ada, ... Richard Damon <Richard@Damon-Family.org> - 2021-04-19 18:09 -0400
                Re: C++, Ada, ... David Brown <david.brown@hesbynett.no> - 2021-04-20 06:58 +0200
                Re: C++, Ada, ... Paul Rubin <no.email@nospam.invalid> - 2021-04-19 23:18 -0700
                Re: C++, Ada, ... David Brown <david.brown@hesbynett.no> - 2021-04-20 09:36 +0200
              Re: C++, Ada, ... Paul Rubin <no.email@nospam.invalid> - 2021-04-19 12:20 -0700
                Re: C++, Ada, ... Niklas Holsti <niklas.holsti@tidorum.invalid> - 2021-04-20 00:26 +0300
                Re: C++, Ada, ... Paul Rubin <no.email@nospam.invalid> - 2021-04-19 16:01 -0700
                Re: C++, Ada, ... Niklas Holsti <niklas.holsti@tidorum.invalid> - 2021-04-20 10:47 +0300
                Re: C++, Ada, ... Tom Gardner <spamjunk@blueyonder.co.uk> - 2021-04-19 23:30 +0100
    Re: C++, Ada, ... Clifford Heath <no.spam@please.net> - 2021-04-18 08:29 +1000
    Re: C++, Ada, ... Niklas Holsti <niklas.holsti@tidorum.invalid> - 2021-04-18 10:39 +0300
      Re: C++, Ada, ... David Brown <david.brown@hesbynett.no> - 2021-04-18 14:59 +0200
        Re: C++, Ada, ... Niklas Holsti <niklas.holsti@tidorum.invalid> - 2021-04-18 19:23 +0300
          Re: C++, Ada, ... David Brown <david.brown@hesbynett.no> - 2021-04-18 19:26 +0200
            Re: C++, Ada, ... Tom Gardner <spamjunk@blueyonder.co.uk> - 2021-04-18 19:29 +0100
              Re: C++, Ada, ... David Brown <david.brown@hesbynett.no> - 2021-04-18 22:23 +0200
                Re: C++, Ada, ... Tom Gardner <spamjunk@blueyonder.co.uk> - 2021-04-18 23:09 +0100
                Re: C++, Ada, ... David Brown <david.brown@hesbynett.no> - 2021-04-19 08:56 +0200
                Re: C++, Ada, ... Niklas Holsti <niklas.holsti@tidorum.invalid> - 2021-04-19 14:04 +0300
                Re: C++, Ada, ... Dimiter_Popoff <dp@tgi-sci.com> - 2021-04-19 15:16 +0300
                Re: C++, Ada, ... Paul Rubin <no.email@nospam.invalid> - 2021-04-19 12:47 -0700
                Re: C++, Ada, ... Niklas Holsti <niklas.holsti@tidorum.invalid> - 2021-04-20 00:37 +0300
                Re: C++, Ada, ... David Brown <david.brown@hesbynett.no> - 2021-04-20 07:50 +0200
                Re: C++, Ada, ... David Brown <david.brown@hesbynett.no> - 2021-04-19 14:26 +0200
            Re: C++, Ada, ... Tom Gardner <spamjunk@blueyonder.co.uk> - 2021-04-18 19:30 +0100
              Re: C++, Ada, ... David Brown <david.brown@hesbynett.no> - 2021-04-18 22:17 +0200
                Re: C++, Ada, ... Tom Gardner <spamjunk@blueyonder.co.uk> - 2021-04-18 23:17 +0100
                Re: C++, Ada, ... David Brown <david.brown@hesbynett.no> - 2021-04-19 08:52 +0200
                Re: C++, Ada, ... Tom Gardner <spamjunk@blueyonder.co.uk> - 2021-04-19 10:08 +0100
                Re: C++, Ada, ... David Brown <david.brown@hesbynett.no> - 2021-04-19 12:15 +0200
                Re: C++, Ada, ... Tom Gardner <spamjunk@blueyonder.co.uk> - 2021-04-19 12:00 +0100
                Re: C++, Ada, ... Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2021-04-19 16:15 +0300
                Re: C++, Ada, ... David Brown <david.brown@hesbynett.no> - 2021-04-19 15:43 +0200
    Re: C++, Ada, ... pozz <pozzugno@gmail.com> - 2021-04-19 18:38 +0200
      Re: C++, Ada, ... Paul Rubin <no.email@nospam.invalid> - 2021-04-19 10:48 -0700
      Re: C++, Ada, ... Tom Gardner <spamjunk@blueyonder.co.uk> - 2021-04-19 19:33 +0100
        Re: C++, Ada, ... Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2021-04-20 15:09 +0300
          Re: C++, Ada, ... Tom Gardner <spamjunk@blueyonder.co.uk> - 2021-04-20 15:29 +0100
      Re: C++, Ada, ... David Brown <david.brown@hesbynett.no> - 2021-04-19 22:48 +0200
        Re: C++, Ada, ... pozz <pozzugno@gmail.com> - 2021-04-19 23:17 +0200
          Re: C++, Ada, ... Paul Rubin <no.email@nospam.invalid> - 2021-04-19 15:55 -0700
            Re: C++, Ada, ... David Brown <david.brown@hesbynett.no> - 2021-04-20 08:21 +0200
          Re: C++, Ada, ... David Brown <david.brown@hesbynett.no> - 2021-04-20 08:20 +0200
  Re: C++, Ada, ... Dave Nadler <drn@nadler.com> - 2021-04-17 21:07 -0400
    Re: C++, Ada, ... Don Y <blockedofcourse@foo.invalid> - 2021-04-17 18:53 -0700
    Re: C++, Ada, ... Tom Gardner <spamjunk@blueyonder.co.uk> - 2021-04-18 09:42 +0100
  Re: C++, Ada, ... dalai lamah <antonio12358@hotmail.com> - 2021-04-18 14:39 +0200

csiph-web