title: Boo/C#: Returning a collection performance
body: <p>I have a function that gets a collection by reference, iterates over it, constructs a new collection of the same length containing updated structs, returns that collection (or rather a reference to it, since it's Boo/C# code).</p>
  
  <p>I'm worried about performance of such a function. Is performance a lot worse than just updating the collection by reference? I need to call this function tens of times per second.</p>
  
  <p>Thank you. Alisa.</p>
  
  <p>P.S.: Why am I doing this? I'm trying to move onto functional programming and make it as pure as possible.</p>