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Re: thread about the pros and cons of lambdas, but more about cons

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Michael S <already5chosen@yahoo.com> writes:

> On Thu, 26 Sep 2024 10:01:11 -0700
> Tim Rentsch <tr.17687@z991.linuxsc.com> wrote:
>
>> Ben Bacarisse <ben@bsb.me.uk> writes:
>>
>>> Ben Bacarisse <ben@bsb.me.uk> writes:
>>>
>>>> ... You can,
>>>> instead, do this (untested):
>>>
>>> I should have tested!  Of course you have to change the capture (at
>>> least for core) from '=' to '&':
>>>
>>>>   #include <functional>
>>>>
>>>>   int floodfill4(
>>>>     unsigned char *grey,
>>>>     int width, int height,
>>>>     int x, int y,
>>>>     unsigned char target, unsigned char dest)
>>>>   {
>>>>     if (width < 1 || height < 1)
>>>>       return 0;
>>>>     if (x < 0 || x >= width || y < 0 || y >= height)
>>>>       return 0;
>>>>
>>>>     size_t w = width, h = height;
>>>>     if (grey[y*w+x] != target)
>>>>       return 0;
>>>>
>>>>     std::function<void(size_t, size_t)> core;
>>>>     core = [&] (size_t x, size_t y) {
>>>
>>> Corrected-----^
>>
>> Why do you think [&] should be used instead of [=]?
>
> Compiler says that otherwise 'core' captures itself before it
> properly initialize.
> And indeed, it does not work (Segmentation fault).

Ahh.  A chicken and egg problem.  I sidestepped that by initializing
'core' as part of its declaration (as my other response to Ben
shows).

No compiler warning, but I didn't try running it.

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thread about the pros and cons of lambdas, but more about cons Michael S <already5chosen@yahoo.com> - 2024-09-25 19:54 +0300
  Re: thread about the pros and cons of lambdas, but more about cons Bonita Montero <Bonita.Montero@gmail.com> - 2024-09-25 19:17 +0200
  Re: thread about the pros and cons of lambdas, but more about cons Bonita Montero <Bonita.Montero@gmail.com> - 2024-09-25 19:55 +0200
  Re: thread about the pros and cons of lambdas, but more about cons Paavo Helde <eesnimi@osa.pri.ee> - 2024-09-25 22:53 +0300
    Re: thread about the pros and cons of lambdas, but more about cons Michael S <already5chosen@yahoo.com> - 2024-09-25 23:30 +0300
      Re: thread about the pros and cons of lambdas, but more about cons Paavo Helde <eesnimi@osa.pri.ee> - 2024-09-26 00:04 +0300
        Re: thread about the pros and cons of lambdas, but more about cons Michael S <already5chosen@yahoo.com> - 2024-09-26 11:17 +0300
        Re: thread about the pros and cons of lambdas, but more about cons Paavo Helde <eesnimi@osa.pri.ee> - 2024-09-26 11:25 +0300
          Re: thread about the pros and cons of lambdas, but more about cons Bonita Montero <Bonita.Montero@gmail.com> - 2024-09-26 10:28 +0200
            Re: thread about the pros and cons of lambdas, but more about cons Paavo Helde <eesnimi@osa.pri.ee> - 2024-09-26 11:49 +0300
          Re: thread about the pros and cons of lambdas, but more about cons Michael S <already5chosen@yahoo.com> - 2024-09-26 11:38 +0300
  Re: thread about the pros and cons of lambdas, but more about cons Ben Bacarisse <ben@bsb.me.uk> - 2024-09-25 23:13 +0100
    Re: thread about the pros and cons of lambdas, but more about cons Ben Bacarisse <ben@bsb.me.uk> - 2024-09-25 23:28 +0100
      Re: thread about the pros and cons of lambdas, but more about cons Michael S <already5chosen@yahoo.com> - 2024-09-26 10:41 +0300
        Re: thread about the pros and cons of lambdas, but more about cons David Brown <david.brown@hesbynett.no> - 2024-09-26 10:29 +0200
          Re: thread about the pros and cons of lambdas, but more about cons Bonita Montero <Bonita.Montero@gmail.com> - 2024-09-26 11:35 +0200
            Re: thread about the pros and cons of lambdas, but more about cons David Brown <david.brown@hesbynett.no> - 2024-09-26 13:27 +0200
              Re: thread about the pros and cons of lambdas, but more about cons Bonita Montero <Bonita.Montero@gmail.com> - 2024-09-26 13:31 +0200
                Re: thread about the pros and cons of lambdas, but more about cons Michael S <already5chosen@yahoo.com> - 2024-09-26 15:25 +0300
                Re: thread about the pros and cons of lambdas, but more about cons Bonita Montero <Bonita.Montero@gmail.com> - 2024-09-26 14:58 +0200
                Re: thread about the pros and cons of lambdas, but more about cons Michael S <already5chosen@yahoo.com> - 2024-09-26 16:53 +0300
                Re: thread about the pros and cons of lambdas, but more about cons Bonita Montero <Bonita.Montero@gmail.com> - 2024-09-26 15:54 +0200
        Re: thread about the pros and cons of lambdas, but more about cons Michael S <already5chosen@yahoo.com> - 2024-09-27 16:55 +0300
      Re: thread about the pros and cons of lambdas, but more about cons Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-09-26 10:01 -0700
        Re: thread about the pros and cons of lambdas, but more about cons Bonita Montero <Bonita.Montero@gmail.com> - 2024-09-26 19:04 +0200
        Re: thread about the pros and cons of lambdas, but more about cons Michael S <already5chosen@yahoo.com> - 2024-09-26 20:20 +0300
          Re: thread about the pros and cons of lambdas, but more about cons Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-09-26 10:38 -0700
            Re: thread about the pros and cons of lambdas, but more about cons Michael S <already5chosen@yahoo.com> - 2024-09-27 16:27 +0300
              Re: thread about the pros and cons of lambdas, but more about cons Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-09-28 04:06 -0700
    Re: thread about the pros and cons of lambdas, but more about cons Michael S <already5chosen@yahoo.com> - 2024-09-26 10:58 +0300
    Re: thread about the pros and cons of lambdas, but more about cons Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-09-26 10:27 -0700
      Re: thread about the pros and cons of lambdas, but more about cons Bonita Montero <Bonita.Montero@gmail.com> - 2024-09-26 19:32 +0200
  Re: thread about the pros and cons of lambdas, but more about cons Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-09-26 14:09 -0700
    Re: thread about the pros and cons of lambdas, but more about cons Michael S <already5chosen@yahoo.com> - 2024-09-27 16:15 +0300
      Re: thread about the pros and cons of lambdas, but more about cons Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-09-28 04:25 -0700

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