Re: Type-safety and C++, was: Re: Dimension of a matrix

From	Stefan Reuther <stefan.news@arcor.de>
Newsgroups	comp.arch.embedded
Subject	Re: Type-safety and C++, was: Re: Dimension of a matrix
Date	2017-03-25 09:59 +0100
Message-ID	<ob5f2r.3s4.1@stefan.msgid.phost.de> (permalink)
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Am 25.03.2017 um 01:32 schrieb Tim Wescott:
> On Fri, 24 Mar 2017 18:24:44 +0000, Simon Clubley wrote:
>> On 2017-03-24, David Brown <david.brown@hesbynett.no> wrote:
>>> On 24/03/17 07:21, Paul Rubin wrote:
>>>> Tim Wescott <seemywebsite@myfooter.really> writes:
>>>>> Is there anything in the standard libraries that does this easy and
>>>>> obvious thing?
>>>>
>>>> In full-fat C++ systems it's preferable to use STL containers for
>>>> arrays instead of using hacky C-style pointers to simulate them.  On
>>>> embedded devices STL might be considered too much bloat though.
>>>>
>>> std::array should involve no "bloat" whatsoever.  It's basically a
>>> type-safe wrapper around C arrays, with the dimension easily available.
>>>
>> Well, "type-safe" if you ignore the little fact that the normal indexing
>> operator "[]" is not bounds checked. :-)

Then it would again be "bloat" compared to a regular array...

>> In the C++ library, it would be nice if the indexing operator most
>> people would use by default, "[]", was the bounds checked one and the
>> alternative indexing operator, "at()", was the non-bounds checked one.
>> That way, you would have to do something unusual in your code to turn
>> _off_ bounds checking instead of having to do something unusual in your
>> code to turn _on_ bounds checking...
> 
> Even better (for me) would be if there were a define that could turn 
> bounds checking on -- that way I could do testing with bounds checking 
> on, and release (presumably faster) code with bounds checking off.

As far as I understand, such a thing would be a legal C++ implementation
(bounds violations are undefined behaviour, which means an
implementation could define it as "raises an exception" or "writes a
coredump"), so bug your compiler maker until they implement that :-)
(Don't we already have some "checked" STL implementations?)


  Stefan

Thread

Dimension of a matrix Tim Wescott <seemywebsite@myfooter.really> - 2017-03-23 18:17 -0500
  Re: Dimension of a matrix Paul Rubin <no.email@nospam.invalid> - 2017-03-23 23:21 -0700
    Re: Dimension of a matrix David Brown <david.brown@hesbynett.no> - 2017-03-24 09:18 +0100
      Type-safety and C++, was: Re: Dimension of a matrix Simon Clubley <clubley@remove_me.eisner.decus.org-Earth.UFP> - 2017-03-24 18:24 +0000
        Re: Type-safety and C++, was: Re: Dimension of a matrix Tim Wescott <tim@seemywebsite.com> - 2017-03-24 19:32 -0500
          Re: Type-safety and C++, was: Re: Dimension of a matrix Stefan Reuther <stefan.news@arcor.de> - 2017-03-25 09:59 +0100
          Re: Type-safety and C++, was: Re: Dimension of a matrix Les Cargill <lcargill99@comcast.com> - 2017-03-25 13:08 -0500
        Re: Type-safety and C++, was: Re: Dimension of a matrix David Brown <david.brown@hesbynett.no> - 2017-03-25 01:57 +0100
          Re: Type-safety and C++, was: Re: Dimension of a matrix Clifford Heath <no.spam@please.net> - 2017-03-25 18:34 +1100
            Re: Type-safety and C++, was: Re: Dimension of a matrix Simon Clubley <clubley@remove_me.eisner.decus.org-Earth.UFP> - 2017-03-26 23:53 +0000
              Re: Type-safety and C++, was: Re: Dimension of a matrix David Brown <david.brown@hesbynett.no> - 2017-03-27 09:51 +0200
                Re: Type-safety and C++, was: Re: Dimension of a matrix Clifford Heath <no.spam@please.net> - 2017-03-27 20:19 +1100
                Re: Type-safety and C++, was: Re: Dimension of a matrix David Brown <david.brown@hesbynett.no> - 2017-03-27 12:17 +0200
          Re: Type-safety and C++, was: Re: Dimension of a matrix Paul Rubin <no.email@nospam.invalid> - 2017-03-25 09:20 -0700
        Re: Type-safety and C++, was: Re: Dimension of a matrix George Neuner <gneuner2@comcast.net> - 2017-03-24 23:14 -0400
          Re: Type-safety and C++, was: Re: Dimension of a matrix Tim Wescott <tim@seemywebsite.com> - 2017-03-25 11:07 -0500
            Re: Type-safety and C++, was: Re: Dimension of a matrix George Neuner <gneuner2@comcast.net> - 2017-03-26 05:45 -0400
              Re: Type-safety and C++, was: Re: Dimension of a matrix Wouter van Ooijen <wouter@voti.nl> - 2017-03-26 13:14 +0200
                Re: Type-safety and C++, was: Re: Dimension of a matrix Paul Rubin <no.email@nospam.invalid> - 2017-03-26 11:08 -0700
                Re: Type-safety and C++, was: Re: Dimension of a matrix Wouter van Ooijen <wouter@voti.nl> - 2017-03-26 20:24 +0200
              Re: Type-safety and C++, was: Re: Dimension of a matrix Tim Wescott <tim@seemywebsite.com> - 2017-03-26 15:16 -0500
                Re: Type-safety and C++, was: Re: Dimension of a matrix Simon Clubley <clubley@remove_me.eisner.decus.org-Earth.UFP> - 2017-03-27 00:09 +0000
                Re: Type-safety and C++, was: Re: Dimension of a matrix Tim Wescott <seemywebsite@myfooter.really> - 2017-03-26 19:43 -0500
                Re: Type-safety and C++, was: Re: Dimension of a matrix Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-03-27 16:57 +0100
                Re: Type-safety and C++, was: Re: Dimension of a matrix Tim Wescott <tim@seemywebsite.com> - 2017-03-27 11:53 -0500
                Re: Type-safety and C++, was: Re: Dimension of a matrix David Brown <david.brown@hesbynett.no> - 2017-03-27 22:04 +0200
                Re: Type-safety and C++, was: Re: Dimension of a matrix Tim Wescott <seemywebsite@myfooter.really> - 2017-03-27 18:32 -0500
                Re: Type-safety and C++, was: Re: Dimension of a matrix Clifford Heath <no.spam@please.net> - 2017-03-28 11:03 +1100
                Re: Type-safety and C++, was: Re: Dimension of a matrix Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-03-27 22:07 +0100
                Re: Type-safety and C++, was: Re: Dimension of a matrix Paul Rubin <no.email@nospam.invalid> - 2017-03-27 23:42 -0700
                Re: Type-safety and C++, was: Re: Dimension of a matrix David Brown <david.brown@hesbynett.no> - 2017-03-28 09:22 +0200
                Re: Type-safety and C++, was: Re: Dimension of a matrix Paul Rubin <no.email@nospam.invalid> - 2017-03-28 00:42 -0700
                Re: Type-safety and C++, was: Re: Dimension of a matrix Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-03-28 09:07 +0100
                Re: Type-safety and C++, was: Re: Dimension of a matrix Les Cargill <lcargill99@comcast.com> - 2017-03-28 19:34 -0500
                Re: Type-safety and C++, was: Re: Dimension of a matrix Tim Wescott <tim@seemywebsite.com> - 2017-03-29 11:39 -0500
                Re: Type-safety and C++, was: Re: Dimension of a matrix Les Cargill <lcargill99@comcast.com> - 2017-03-28 19:29 -0500
                Re: Type-safety and C++, was: Re: Dimension of a matrix David Brown <david.brown@hesbynett.no> - 2017-03-29 10:31 +0200
                Re: Type-safety and C++, was: Re: Dimension of a matrix Simon Clubley <clubley@remove_me.eisner.decus.org-Earth.UFP> - 2017-03-30 00:23 +0000
                Re: Type-safety and C++, was: Re: Dimension of a matrix Les Cargill <lcargill99@comcast.com> - 2017-03-29 19:31 -0500
                Re: Type-safety and C++, was: Re: Dimension of a matrix Phil Martel <pomartel@comcast.net> - 2017-03-30 11:51 -0400
                Re: Type-safety and C++, was: Re: Dimension of a matrix Les Cargill <lcargill99@comcast.com> - 2017-03-30 19:16 -0500
                Re: Type-safety and C++, was: Re: Dimension of a matrix David Brown <david.brown@hesbynett.no> - 2017-03-31 09:21 +0200
                Re: Type-safety and C++, was: Re: Dimension of a matrix Tim Wescott <seemywebsite@myfooter.really> - 2017-03-28 14:19 -0500
    Re: Dimension of a matrix Tim Wescott <tim@seemywebsite.com> - 2017-03-24 11:05 -0500
      Re: Dimension of a matrix David Brown <david.brown@hesbynett.no> - 2017-03-24 17:33 +0100
        Re: Dimension of a matrix Tim Wescott <tim@seemywebsite.com> - 2017-03-24 12:09 -0500
      Re: Dimension of a matrix Les Cargill <lcargill99@comcast.com> - 2017-03-25 13:09 -0500
    Re: Dimension of a matrix Les Cargill <lcargill99@comcast.com> - 2017-03-25 13:05 -0500
  Re: Dimension of a matrix David Brown <david.brown@hesbynett.no> - 2017-03-24 09:20 +0100
    Re: Dimension of a matrix Les Cargill <lcargill99@comcast.com> - 2017-03-25 13:12 -0500
      Re: Dimension of a matrix Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2017-03-25 20:08 +0100
        Re: Dimension of a matrix Les Cargill <lcargill99@comcast.com> - 2017-03-25 15:17 -0500
          Re: Dimension of a matrix David Brown <david.brown@hesbynett.no> - 2017-03-26 17:32 +0200
            Re: Dimension of a matrix Les Cargill <lcargill99@comcast.com> - 2017-03-26 11:55 -0500
              Re: Dimension of a matrix David Brown <david.brown@hesbynett.no> - 2017-03-26 21:23 +0200
                Re: Dimension of a matrix Les Cargill <lcargill99@comcast.com> - 2017-03-29 19:36 -0500
                Re: Dimension of a matrix Simon Clubley <clubley@remove_me.eisner.decus.org-Earth.UFP> - 2017-03-30 00:36 +0000
                Re: Dimension of a matrix Paul Rubin <no.email@nospam.invalid> - 2017-03-29 19:55 -0700
                Re: Dimension of a matrix David Brown <david.brown@hesbynett.no> - 2017-03-30 09:49 +0200
                Re: Dimension of a matrix Simon Clubley <clubley@remove_me.eisner.decus.org-Earth.UFP> - 2017-03-30 18:07 +0000
                Re: Dimension of a matrix David Brown <david.brown@hesbynett.no> - 2017-03-30 09:47 +0200
  Re: Dimension of a matrix Wouter van Ooijen <wouter@voti.nl> - 2017-03-25 19:08 +0100
    Re: Dimension of a matrix Les Cargill <lcargill99@comcast.com> - 2017-03-25 15:21 -0500
      Re: Dimension of a matrix Wouter van Ooijen <wouter@voti.nl> - 2017-03-26 14:43 +0200

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