title: Check if a variable type is iterable?
body: <p>Is there any way to check if an arbitrary variable type is iterable? </p>
  
  <p>So to check if it has indexed elements or I can actually loop over it's children? (Use foreach for example?)</p>
  
  <p>Is it possible to create a universal template for that?</p>
  
  <p>I've found techniques for other programming languages while searching for it. Yet still have to find out how to do this in C++.</p>