title: Would a c++ class/struct be noticeably slower than a c-array in heavy simulation codes
body: <p>Creating a data class/struct is said to be slower than a c-array due to addition of "different levels of indirection" and is apparently 'false' as found <a href="http://www.cplusplus.com/forum/beginner/46935/" rel="nofollow">here</a>.  I've been working on a simulation code for awhile and, although I know people always say to not pre-optimize, knowing what data structures to use is essential before you get in too deep.  </p>
  
  <p>If I am going to run >10,000 main loops with anywhere from 1->50 'mini-loops' and maybe even 1->10 'mini-mini-loops' (ie, a maximum of say ~10,000,000 loops in total), would it be beneficial to keep all my data in c code? Or is the difference in speed insignificant enough that I can utilize classes so as to not write one large c file?</p>