Re: Using local variables in C callbacks

From	Juha Nieminen <nospam@thanks.invalid>
Newsgroups	comp.lang.c++
Subject	Re: Using local variables in C callbacks
Date	2022-09-12 06:03 +0000
Organization	Aioe.org NNTP Server
Message-ID	<tfmi2j$1bua$1@gioia.aioe.org> (permalink)
References	<tfku77$1vir2$1@dont-email.me>

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Bonita Montero <Bonita.Montero@gmail.com> wrote:
> using namespace std;
> 
> int main()
> {
>        vector<string> images;
>        auto fnDlIterate = bind(
>                [&]( dl_phdr_info *image, size_t size ) -> int
>                {
>                        try
>                        {
>                                images.emplace_back( image->dlpi_name );
>                        }
>                        catch( bad_alloc const & )
>                        {
>                                return 1;
>                        }
>                        return 0;
>                }, placeholders::_1, placeholders::_2 );
>        using fn_callback_t = decltype(fnDlIterate);
>        if( dl_iterate_phdr(
>                []( dl_phdr_info *image, size_t size, void *pFn ) -> int
>                {
>                        return (*(fn_callback_t *)pFn)( image, size );
>                }, &fnDlIterate ) )
>                return EXIT_FAILURE;

I think this demonstrates beautifully why you shouldn't use "using
namespace std;"

The code is full of obfuscated names and it's very difficult to see with
a visual scan which names are declared locally, which are from the
standard library, and which are from some third-party library.

Also, I thought that lambdas made std::bind() obsolete.

Thread

Using local variables in C callbacks Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-11 17:18 +0200
  Re: Using local variables in C callbacks Muttley@dastardlyhq.com - 2022-09-11 15:45 +0000
    Re: Using local variables in C callbacks Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-11 17:51 +0200
      Re: Using local variables in C callbacks Muttley@dastardlyhq.com - 2022-09-11 15:53 +0000
        Re: Using local variables in C callbacks Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-11 17:57 +0200
          Re: Using local variables in C callbacks Tony Oliver <guinness.tony@gmail.com> - 2022-09-12 17:05 -0700
            Re: Using local variables in C callbacks Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-13 07:18 +0200
  Re: Using local variables in C callbacks Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-12 07:02 +0200
  Re: Using local variables in C callbacks Juha Nieminen <nospam@thanks.invalid> - 2022-09-12 06:03 +0000
    Re: Using local variables in C callbacks Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-12 09:16 +0200
      Re: Using local variables in C callbacks Juha Nieminen <nospam@thanks.invalid> - 2022-09-13 06:52 +0000
        Re: Using local variables in C callbacks Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-13 12:09 +0200
          Re: Using local variables in C callbacks Juha Nieminen <nospam@thanks.invalid> - 2022-09-13 12:57 +0000
            Re: Using local variables in C callbacks Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-13 15:57 +0200
              Re: Using local variables in C callbacks Juha Nieminen <nospam@thanks.invalid> - 2022-09-14 06:08 +0000
                Re: Using local variables in C callbacks Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-14 09:00 +0200
                Re: Using local variables in C callbacks Juha Nieminen <nospam@thanks.invalid> - 2022-09-14 12:26 +0000
                Re: Using local variables in C callbacks Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-14 14:59 +0200
                Re: Using local variables in C callbacks David Brown <david.brown@hesbynett.no> - 2022-09-14 16:01 +0200
                Re: Using local variables in C callbacks Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-14 16:49 +0200
                Re: Using local variables in C callbacks Juha Nieminen <nospam@thanks.invalid> - 2022-09-15 05:35 +0000
                Re: Using local variables in C callbacks Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-15 08:26 +0200
                Re: Using local variables in C callbacks scott@slp53.sl.home (Scott Lurndal) - 2022-09-15 14:09 +0000
                Re: Using local variables in C callbacks Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-15 16:56 +0200
                Re: Using local variables in C callbacks Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-09-15 05:43 -0700
                Re: Using local variables in C callbacks Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-15 16:02 +0200
                Re: Using local variables in C callbacks Juha Nieminen <nospam@thanks.invalid> - 2022-09-16 06:08 +0000
                Re: Using local variables in C callbacks Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-16 13:43 +0200
                Re: Using local variables in C callbacks Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-09-16 06:57 -0700
                Re: Using local variables in C callbacks Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-09-16 10:13 -0700
                Re: Using local variables in C callbacks "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-09-14 15:38 -0700
          Re: Using local variables in C callbacks Öö Tiib <ootiib@hot.ee> - 2022-09-13 22:20 -0700
        Re: Using local variables in C callbacks "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-09-13 12:48 -0700
          Re: Using local variables in C callbacks Juha Nieminen <nospam@thanks.invalid> - 2022-09-14 06:09 +0000
            Re: Using local variables in C callbacks "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-09-15 13:29 -0700

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