function pointer vs functors in C++
<p>What is the difference between using functors and function pointers.
For example</p>

<pre><code>  //Functor
  struct add_x
  {
    int x;
    add_x(int y):x(y){}
    int operator()(int y)
    {
       return x+y;
    }
  };
  //Function
  int (func)(int x)
  {
     return ++x;
  }
  std::vector&lt;int&gt; vec();
  //fill vec with 1 2 3 4 5
  int (*f)(int) = func;//Function pointer
  std::transform(vec.begin(),vec.end(),f); //approach 1
  std::transform(vec.begin(),vec.end(),add_x(1)); //approach 2
</code></pre>

<p>Both approaches work but i am sure there will be cases where one is preferred(or possible) over other.</p>