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Re: Let's do that functional

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Bonita Montero wrote:
> I wanted to check the typed of different Win32 HANDLEs. Although this
> is documented I wanted to do that myself. I did that with the functional
> programming style I love so much
(Yours is not the functional style but hybrid at best
  (because
   (functional programmers don't use
    (or
     (iterative loops)
     (mutable variables
      (truly functional programmers don't use mutable variables either)
      (hence functional programmers don't use cout
       (and not only because of the above))))))
  (-Pavel))

> - having code in an initializer_list<>.
> 
> #include <WinSock2.h>
> #include <Windows.h>
> #include <iostream>
> #include <functional>
> #include <system_error>
> 
> using namespace std;
> 
> int main( int argc, char **argv )
> {
>      WSADATA wsaData;
>      (void)WSAStartup( MAKEWORD(2, 2), &wsaData );
>      using fn_ret_t = pair<char const *, HANDLE>;
>      using fn_t = function<fn_ret_t ()>;
>      static fn_t const functions[] =
>      {
>          [&]() -> fn_ret_t
>          {
>              if( argc < 1 || !argv[0] )
>                  return { nullptr, NULL };
>              return { "file: ", CreateFileA( argv[0], GENERIC_READ, 
> FILE_SHARE_READ, nullptr, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL ) };
>          },
>          []() -> fn_ret_t { return { "stdin: ", GetStdHandle( 
> STD_INPUT_HANDLE ) }; },
>          []() -> fn_ret_t { return { "TCP-socket: ", (HANDLE)socket( 
> AF_INET, SOCK_STREAM, IPPROTO_TCP ) }; },
>          []() -> fn_ret_t { return { "UDP-socket: ", (HANDLE)socket( 
> AF_INET, SOCK_DGRAM, IPPROTO_UDP ) }; },
>          []() -> fn_ret_t { return { "ICMP-socket: ", (HANDLE)socket( 
> AF_INET, SOCK_RAW, IPPROTO_ICMP ) }; }
>      };
>      using map_t = pair<DWORD, char const*>;
>      static map_t const mappings[] =
>      {
>          { FILE_TYPE_CHAR, "FILE_TYPE_CHAR" },
>          { FILE_TYPE_DISK, "FILE_TYPE_DISK" },
>          { FILE_TYPE_PIPE, "FILE_TYPE_PIPE" },
>          { FILE_TYPE_REMOTE, "FILE_TYPE_REMOTE" },
>          { FILE_TYPE_UNKNOWN, "FILE_TYPE_UNKNOWN" }
>      };
>      for( fn_t const &fn : functions )
>          if( fn_ret_t fr = fn(); fr.first && fr.second )
>          {
>              DWORD dwFileType = GetFileType( fr.second );
>              map_t const *type = find_if( mappings, end( mappings ), 
> [&]( map_t const &mapEntry ) { return mapEntry.first == dwFileType; } );
>              if( type == end( mappings ) )
>                  continue;
>              cout << fr.first << type->second << endl;
>          }
> }

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Thread

Let's do that functional Bonita Montero <Bonita.Montero@gmail.com> - 2023-08-15 09:15 +0200
  Re: Let's do that functional "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2023-08-15 16:02 +0200
    Re: Let's do that functional Bonita Montero <Bonita.Montero@gmail.com> - 2023-08-15 17:16 +0200
  Re: Let's do that functional Pavel <pauldontspamtolk@removeyourself.dontspam.yahoo> - 2023-08-15 23:44 -0400
    Re: Let's do that functional Bonita Montero <Bonita.Montero@gmail.com> - 2023-08-16 10:25 +0200
      Re: Let's do that functional Pavel <pauldontspamtolk@removeyourself.dontspam.yahoo> - 2023-08-16 21:56 -0400
  Re: Let's do that functional Andrey Tarasevich <andreytarasevich@hotmail.com> - 2023-08-18 07:37 -0700
    Re: Let's do that functional Bonita Montero <Bonita.Montero@gmail.com> - 2023-08-18 17:43 +0200

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