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Re: Initializing iterators to one past end() in for loops

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Nikos Chantziaras wrote:

> Is there some simple way to convert this:
> 
>    std::vector<int> vec;
>    // ...
>    for (size_t i = 1; i < vec.size(); ++i)
>        // do something with vec[i]
> 
> to a for-loop that uses iterators?  I've tried:
> 
>    typedef std::vector<int>::iterator it_t;
>    for (it_t i = vec.begin() + 1; i != vec.end(); ++i)
>        // do something with *i
> 
> but I'm not surprised that it doesn't work.

Iterators for std::vector<> are random access. Hence, they are <-comparable 
and you can add integers to them. So, you should be able to translate one-
to-one:

  for ( std::vector<int>::iterator iter = vec.begin() + 1;
        iter < vec.end(); ++ iter ) {
    // do something with *iter
  }

The stop-condition iter != vec.end() is broken for empty vectors.


Best,

Kai-Uwe Bux

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Thread

Initializing iterators to one past end() in for loops Nikos Chantziaras <realnc@arcor.de> - 2011-04-14 00:38 +0300
  Re: Initializing iterators to one past end() in for loops Leigh Johnston <leigh@i42.co.uk> - 2011-04-13 22:46 +0100
  Re: Initializing iterators to one past end() in for loops Kai-Uwe Bux <jkherciueh@gmx.net> - 2011-04-13 23:48 +0200
    Re: Initializing iterators to one past end() in for loops Leigh Johnston <leigh@i42.co.uk> - 2011-04-13 22:50 +0100
      Re: Initializing iterators to one past end() in for loops Kai-Uwe Bux <jkherciueh@gmx.net> - 2011-04-14 00:23 +0200
        Re: Initializing iterators to one past end() in for loops Kai-Uwe Bux <jkherciueh@gmx.net> - 2011-04-14 00:32 +0200
          Re: Initializing iterators to one past end() in for loops Noah Roberts <dont@email.me> - 2011-04-13 17:16 -0700
            Re: Initializing iterators to one past end() in for loops Kai-Uwe Bux <jkherciueh@gmx.net> - 2011-04-14 05:57 +0200
              Re: Initializing iterators to one past end() in for loops Leigh Johnston <leigh@i42.co.uk> - 2011-04-14 14:29 +0100
                Re: Initializing iterators to one past end() in for loops Kai-Uwe Bux <jkherciueh@gmx.net> - 2011-04-14 17:57 +0200
                Re: Initializing iterators to one past end() in for loops Leigh Johnston <leigh@i42.co.uk> - 2011-04-14 17:56 +0100
                Re: Initializing iterators to one past end() in for loops Kai-Uwe Bux <jkherciueh@gmx.net> - 2011-04-14 19:33 +0200
              Re: Initializing iterators to one past end() in for loops Noah Roberts <dont@email.me> - 2011-04-14 09:54 -0700
                Re: Initializing iterators to one past end() in for loops Kai-Uwe Bux <jkherciueh@gmx.net> - 2011-04-14 20:08 +0200
  Re: Initializing iterators to one past end() in for loops gwowen <gwowen@gmail.com> - 2011-04-13 14:49 -0700
  Re: Initializing iterators to one past end() in for loops Sam <sam@email-scan.com> - 2011-04-13 16:58 -0500
  Re: Initializing iterators to one past end() in for loops Nikos Chantziaras <realnc@arcor.de> - 2011-04-14 01:07 +0300
    Re: Initializing iterators to one past end() in for loops Ian Collins <ian-news@hotmail.com> - 2011-04-14 10:12 +1200
    Re: Initializing iterators to one past end() in for loops gwowen <gwowen@gmail.com> - 2011-04-13 15:24 -0700
    Re: Initializing iterators to one past end() in for loops Paavo Helde <myfirstname@osa.pri.ee> - 2011-04-13 23:05 -0500
      Re: Initializing iterators to one past end() in for loops Ian Collins <ian-news@hotmail.com> - 2011-04-14 16:20 +1200
        Re: Initializing iterators to one past end() in for loops Paavo Helde <myfirstname@osa.pri.ee> - 2011-04-13 23:52 -0500
        Re: Initializing iterators to one past end() in for loops Jeff Flinn <TriumphSprint2000@hotmail.com> - 2011-04-14 07:49 -0400
      Re: Initializing iterators to one past end() in for loops Nikos Chantziaras <realnc@arcor.de> - 2011-04-14 21:45 +0300

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