Re: initializing a vector with a sequence of 0, ..., N-1

From:

Rene =?iso-8859-1?Q?M=F6hring?= <rene_moehring@gmx.de>

Newsgroups:

comp.lang.c++.moderated

Date:

24 Apr 2006 16:03:59 -0400

Message-ID:

<fc4i2e.o41.ln@thyrfing.homeunix.net>

Carl Barron <cbarron413@adelphia.net> schrieb:

In article <444A7408.20301@iitis.gliwice.pl>, Irek Szczesniak
<ijs@iitis.gliwice.pl> wrote:

I want to initialize a vector of N elements with the integer numbers
from 0 to N-1. What I came up with is this:

#include <vector>
#include <algorithm>
#include <iterator>
#include <iostream>

using namespace std;

int main()
{
   vector<int> index(10);
   for(int i = index.size(); i--; index[i] = i);
   copy(index.begin(), index.end(),
        ostream_iterator<int>(cout, "\n"));
   return 0;
}

However, I don't like this, because I can introduce a but when coding
the "for" loop. Do you know some better way of doing it?

For instance, it would be cool to have something like this:

vector<int> index(seq<vector<int> >(0, 9));

Thanks for reading.

   there is
  template <class T>
  class incr
  {
      T x;
   public:
      incr(const T &a):x(a){}
      T operator () () {return x++;}
   };

   ...
   std::vector<int> foo;
   std::generate_n(std::back_inserter(foo),10,incr<int> (0));

This looks really complicated in comparison to the for loop.
--
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