Re: [Boost-users] lambda::var( i )++

Subject: Re: [Boost-users] lambda::var( i )++
From: Christopher Jefferson (chris_at_[hidden])
Date: 2011-03-10 04:01:52

On 9 Mar 2011, at 23:26, er wrote:

> Hello,
> 
> Is there a variant of this
> 
>    int i = 0;
>    lambda::var( i )++;
> 
> in which I can do away with the external variable, i? In other words, a nullary functor that returns 0, 1, 2, successively?

You could write one, something like (not compile tested!)

struct Counter
{
  boost::shared_ptr<int> ptr;
  Counter() : ptr(new int(-1)) {}

  int operator()()
  { 
     *(ptr)++;
     return *ptr;
  }
};