Groups > comp.lang.c++ > #119119

Re: Threads across programming languages

From	wij <wyniijj5@gmail.com>
Newsgroups	comp.lang.c++
Subject	Re: Threads across programming languages
Date	2024-05-15 08:31 +0800
Organization	A noiseless patient Spider
Message-ID	<f7729c241aeac3011efe9267a14fde670b67581d.camel@gmail.com> (permalink)
References	(20 earlier) <v1vfqf$4eq2$1@dont-email.me> <f919090a93e5ab7c32c8961a6061c9e6e38c8fc4.camel@gmail.com> <v1vs6e$7b2f$1@dont-email.me> <126394fbbc6a61aa1257379032ed4fc43689a61c.camel@gmail.com> <v20ht3$cjev$1@dont-email.me>

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On Tue, 2024-05-14 at 23:34 +0300, Paavo Helde wrote:
> On 14.05.2024 22:29, wij wrote:
> > On Tue, 2024-05-14 at 16:24 +0200, David Brown wrote:
> 
> > 
> > > So Tim is completely wrong to say that specifying the variables
> > > accessible in a lambda gives "no real advantages".  It doesn't give the
> > > compiler's code /generator/ any more information than it can deduce
> > > itself from [&] or [=], but it gives more information to the compiler's
> > > code /checker/ and to human programmers - those are big advantages and
> > > greater expressive power.
> > 
> > Probably. I now still hesitate whether or not I should learn and adopt C++'s
> > lambda expression. My consideration is that many new features after C++11
> > are not really necessary and the burden may be greater than the gain for me.
> 
> Lambda is in C++11, not after. Also note that some earlier things have 
> been deprecated and removed from the later C++ versions, so instead of 
> writing this good-and-old C++98 code like:
> 
> endpoints.erase(std::remove_if(endpoints.begin(), endpoints.end(),
>     std::not1(Ice::constMemFun(&EndpointI::datagram))),
>     endpoints.end());
> 
> one might now to have to use a lambda (or an extra function) instead:
> 
> endpoints.erase(std::remove_if(endpoints.begin(), endpoints.end(),
>     [](auto endpoint) {return !endpoint->datagram();}),
>     endpoints.end());
> 
> YMMV, but I like the lambda version more.

That feature should be good but not very significant for me to adopt it.

> 
> > 
> > > > Cpp is just having too many 'syntactic sugars'
> > > > (and keep on adding it) to be away from this goal, IMO.
> > > 
> > > C++ is a very big language, and gains new features (in the language and
> > > standard library) every three years.  While some features make it easier
> > > to write better code, backwards compatibility means it is rarely
> > > possible to remove features that are no longer necessary.  Thus if you
> > > want to be able to read and understand all the syntax of C++, it gets
> > > more effort.  But if you are in the position to be able to deal with C++
> > > code using only the features you find useful and like, then that is much
> > > less of an issue.
> > 
> > I am not optimistic about the future of C++.
> > 
> 
> > > It is perhaps easier to accidentally write code that is big and slow in
> > > C++ than it is in C, but it is certainly not necessary.
> > 
> > My concern is that C++ codes typically consumes more memory much less
> > proportional than the speed gain. Basically, time*space=constant, which is
> > especially observable for computation intensive problems. I am more concerned
> > about the cost of problem solving instead of plain code analysis.
> 
> You have this feeling because with C++ one can solve much more complex 
> tasks than in C. Solving more complex tasks often requires more run 
> time, more memory, or both.
> 
> Still, sometimes one can buy more speed by using more memory (cf quicksort).

This is fact, not 'feeling': An algorithm using x times more memory should be 
x times faster. Although in reality, this is an ideal most of the time for many
programs, the principle is still very true. I am considering what a machine
can do, not a single program can do.

> On the other hand, when processing very large arrays, using an 
> unnecessarily large data type or too bloated structs can start to slow 
> things down. But this has nothing to do with C++. If anything, C++ makes 
> it easier to refactor the code to use a smaller datatype, or to have a 
> templated version supporting multiple datatypes.
> 
> Of course it is possible to write bloatware in C++. But I bet that when 
> some program eats up all your computer memory, it will much more 
> probably be a Java program, not C++ ;-)
> 
> 
> > 
> > > And while it occasionally makes sense to use assembly for the most
> > > time-critical parts of code, it is very common for clear, maintainable C
> > > or C++ code to be /faster/ than clear, maintainable assembly code.
> > > 
> > > Unless you are dealing with something that makes use of processor
> > > instructions or features that are unknown to the C/C++ compiler, writing
> > > assembly code that is faster than C or C++ will often require such
> > > specific care for things like instruction scheduling, register pressure,
> > > cache prefetching, etc., than your results will be far from clear or
> > > maintainable.  And by the time you've got it working, the end user has
> > > bought a new PC and the processor has different numbers of execution
> > > units and more specialised instructions.  You can re-write much of the
> > > assembly, or you can re-compile your C/C++ with a different "-march=" flag.
> > 
> > To me, there is no clear cut saying which (assembly or C/C++) is better just
> > from the view point of common capabilities mutual to low/high level languages.
> > (there are many capabilities C/C++ cannot do, typically involving hardware
> > capabilities, virus, anti-interference, simulation,...)
> > It all depends on what kind of application is desired.
> > Generally, I feel software projects within 6-man-month are no difference from
> > the language choice. One can also program assembly as fast.
> > Those said, I retired earily (at about 37), I use C++ exclusively since then.
> > Many are from my memory and what I received and my observations.
> 
> In our current project codebase there were (are?) some historic pieces 
> from coworkers before year 2000 who were also thinking assembler would 
> be the best choice for their work. Their work has become obsolete 3 
> times by now: when porting the code to Linux, when porting code to 
> x86_64, and when porting code to ARM64. For the past 10 years we do not 
> even compile the project in the original x86 mode any more.
> 
> Guess what? Nobody in the team wanted to learn Linux, ARM and x86_64 
> assemblers just for porting these small pieces of an existing program. 
> The pieces were rewritten in C++ and the original assembler code was 
> promptly forgotten. Good riddance!

Who would use assembly and consider porting to different, incompatible
CPU/platforms?

What is the real meaning of 'porting'? I think a C/C++ program for Window using
its specific libraries is not easily ported to Linux where that libraries are not 
available. This kind of task is usually not really 'porting'.

Assembly has its bads, but considering the fact that writting assembly is 
basically the same as writting high level language except the compilation is 
done by human instead of automated by the compilation tools.
The number of lines of assembly program is usually several times longer than
high level language. But that is just appearance, the complexity is the same.
Many of the extra works can be mechanically (or the like) solved.

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Thread

Re: Threads across programming languages Paavo Helde <eesnimi@osa.pri.ee> - 2024-04-29 19:13 +0300
  Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-04-29 20:29 +0000
    Re: Threads across programming languages "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-04-29 13:33 -0700
      Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-04-29 22:41 +0000
        Re: Threads across programming languages "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-04-29 16:46 -0700
          Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-04-30 00:11 +0000
      Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-01 06:54 +0200
        Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-05-01 07:10 +0000
          Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-01 10:13 +0200
            Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-05-01 08:53 +0000
              Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-01 10:59 +0200
                Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-05-01 20:34 +0000
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-02 05:45 +0200
                Re: Threads across programming languages David Brown <david.brown@hesbynett.no> - 2024-05-02 15:53 +0200
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-02 17:10 +0200
                Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-05-02 23:24 +0000
                Re: Threads across programming languages David Brown <david.brown@hesbynett.no> - 2024-05-03 09:38 +0200
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-03 09:58 +0200
                Re: Threads across programming languages David Brown <david.brown@hesbynett.no> - 2024-05-03 11:18 +0200
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-03 13:23 +0200
                Re: Threads across programming languages Michael S <already5chosen@yahoo.com> - 2024-05-03 18:01 +0300
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-03 17:18 +0200
                Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-05-03 22:20 +0000
                Re: Threads across programming languages Paavo Helde <eesnimi@osa.pri.ee> - 2024-05-04 20:41 +0300
                Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-05-05 01:41 +0000
                Re: Threads across programming languages Paavo Helde <eesnimi@osa.pri.ee> - 2024-05-05 10:38 +0300
                Re: Threads across programming languages Michael S <already5chosen@yahoo.com> - 2024-05-05 12:37 +0300
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-05 13:00 +0200
                Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-05-13 00:43 +0000
                Re: Threads across programming languages Michael S <already5chosen@yahoo.com> - 2024-05-13 15:04 +0300
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-13 16:52 +0200
                Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-05-17 22:18 +0000
                Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-05-17 22:17 +0000
                Re: Threads across programming languages Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-05-06 15:13 -0700
                Re: Threads across programming languages Paavo Helde <eesnimi@osa.pri.ee> - 2024-05-07 08:41 +0300
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-07 11:00 +0200
                Re: Threads across programming languages Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-05-13 19:43 -0700
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-14 04:59 +0200
                Re: Threads across programming languages Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-05-21 16:39 -0700
                Re: Threads across programming languages Paavo Helde <eesnimi@osa.pri.ee> - 2024-05-14 13:53 +0300
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-14 13:42 +0200
                Re: Threads across programming languages wij <wyniijj5@gmail.com> - 2024-05-14 19:55 +0800
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-14 14:11 +0200
                Re: Threads across programming languages wij <wyniijj5@gmail.com> - 2024-05-14 20:16 +0800
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-14 16:02 +0200
                Re: Threads across programming languages "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-14 13:34 -0700
                Re: Threads across programming languages wij <wyniijj5@gmail.com> - 2024-05-14 19:46 +0800
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-14 14:13 +0200
                Re: Threads across programming languages wij <wyniijj5@gmail.com> - 2024-05-14 20:28 +0800
                Re: Threads across programming languages David Brown <david.brown@hesbynett.no> - 2024-05-14 16:24 +0200
                Re: Threads across programming languages wij <wyniijj5@gmail.com> - 2024-05-15 03:29 +0800
                Re: Threads across programming languages Paavo Helde <eesnimi@osa.pri.ee> - 2024-05-14 23:34 +0300
                Re: Threads across programming languages wij <wyniijj5@gmail.com> - 2024-05-15 08:31 +0800
                Re: Threads across programming languages Ross Finlayson <ross.a.finlayson@gmail.com> - 2024-05-14 18:16 -0700
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-15 06:26 +0200
                Re: Threads across programming languages Paavo Helde <eesnimi@osa.pri.ee> - 2024-05-15 11:06 +0300
                Re: Threads across programming languages Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-05-21 16:34 -0700
                Re: Threads across programming languages olcott <polcott333@gmail.com> - 2024-05-21 18:43 -0500
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-15 06:25 +0200
                Re: Threads across programming languages Paavo Helde <eesnimi@osa.pri.ee> - 2024-05-15 20:48 +0300
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-15 06:23 +0200
                Re: Threads across programming languages "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-14 21:37 -0700
                Re: Threads across programming languages wij <wyniijj5@gmail.com> - 2024-05-15 19:57 +0800
                Re: Threads across programming languages wij <wyniijj5@gmail.com> - 2024-05-15 20:07 +0800
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-15 17:33 +0200
                Re: Threads across programming languages "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-15 08:43 -0700
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-15 17:55 +0200
                Re: Threads across programming languages "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-15 10:31 -0700
                Re: Threads across programming languages David Brown <david.brown@hesbynett.no> - 2024-05-15 11:20 +0200
                Re: Threads across programming languages wij <wyniijj5@gmail.com> - 2024-05-15 22:38 +0800
                Re: Threads across programming languages Paavo Helde <eesnimi@osa.pri.ee> - 2024-05-15 20:46 +0300
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-15 21:51 +0200
                Re: Threads across programming languages Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-03 19:30 -0700
                Re: Threads across programming languages David Brown <david.brown@hesbynett.no> - 2024-06-04 09:03 +0200
                Re: Threads across programming languages Michael S <already5chosen@yahoo.com> - 2024-05-15 14:24 +0300
                Re: Threads across programming languages Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-05-21 19:26 -0700
                Re: Threads across programming languages Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-05-21 20:27 -0700
                Re: Threads across programming languages Paavo Helde <eesnimi@osa.pri.ee> - 2024-05-22 11:43 +0300
                Re: Threads across programming languages Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-01 21:03 -0700
                Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-05-02 23:21 +0000
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-03 08:45 +0200
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-03 09:05 +0200
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-03 09:09 +0200
                Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-05-04 02:33 +0000
                Re: Threads across programming languages "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-03 20:05 -0700
                Re: Threads across programming languages "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-03 20:07 -0700
                Re: Threads across programming languages "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-03 20:09 -0700
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-04 06:00 +0200
                Re: Threads across programming languages "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-03 21:19 -0700
                Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-05-05 01:40 +0000
                Re: Threads across programming languages "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-04 22:23 -0700
                Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-05-02 05:39 +0000
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-02 07:53 +0200
                Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-05-02 23:16 +0000
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-03 09:00 +0200
                Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-05-04 02:30 +0000
                Re: Threads across programming languages "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-03 20:36 -0700
                Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-05-04 04:46 +0000
                Re: Threads across programming languages "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-03 21:50 -0700
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-04 06:00 +0200
                Re: Threads across programming languages "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-03 21:27 -0700
                Re: Threads across programming languages "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-02 13:28 -0700
                Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-05-02 23:15 +0000
                Re: Threads across programming languages "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-02 16:58 -0700
                Re: Threads across programming languages Kaz Kylheku <643-408-1753@kylheku.com> - 2024-05-03 00:15 +0000
                Re: Threads across programming languages "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-02 17:22 -0700
                Re: Threads across programming languages "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-03 00:07 -0700
                Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-05-03 02:25 +0000
                Re: Threads across programming languages Ross Finlayson <ross.a.finlayson@gmail.com> - 2024-05-03 12:33 -0700
                Re: Threads across programming languages Ross Finlayson <ross.a.finlayson@gmail.com> - 2024-05-07 20:48 -0700
                Re: Threads across programming languages David Brown <david.brown@hesbynett.no> - 2024-05-03 10:34 +0200
                Re: Threads across programming languages Michael S <already5chosen@yahoo.com> - 2024-05-03 18:05 +0300
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-03 17:20 +0200
                Re: Threads across programming languages Michael S <already5chosen@yahoo.com> - 2024-05-03 18:47 +0300
                Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-05-03 22:19 +0000
                Re: Threads across programming languages bart <bc@freeuk.com> - 2024-05-04 00:27 +0100
                Re: Threads across programming languages Michael S <already5chosen@yahoo.com> - 2024-05-04 22:04 +0300
                Re: Threads across programming languages David Brown <david.brown@hesbynett.no> - 2024-05-05 14:56 +0200
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-04 17:36 +0200
                Re: Threads across programming languages Michael S <already5chosen@yahoo.com> - 2024-05-04 22:11 +0300
                Re: Threads across programming languages "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-04 12:59 -0700
                Re: Threads across programming languages "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-01 22:20 -0700
                Re: Threads across programming languages "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-01 22:22 -0700
              Re: Threads across programming languages "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-01 11:55 -0700
        Re: Threads across programming languages "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-01 11:55 -0700
    Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-01 06:53 +0200
      Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-05-01 07:09 +0000
        Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-01 10:11 +0200
          Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-05-01 08:53 +0000
            Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-01 11:00 +0200
              Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-05-01 20:31 +0000
                Re: Threads across programming languages scott@slp53.sl.home (Scott Lurndal) - 2024-05-01 21:00 +0000
                Re: Threads across programming languages Michael S <already5chosen@yahoo.com> - 2024-05-02 00:05 +0300
                Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-05-01 23:05 +0000
                Re: Threads across programming languages Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-02 05:46 +0200
                Re: Threads across programming languages "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-02 13:33 -0700
                Re: Threads across programming languages Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-05-03 22:22 +0000
  Re: Threads across programming languages scott@slp53.sl.home (Scott Lurndal) - 2024-04-30 16:48 +0000

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