title: Boost mapped_file or file_mapping
body: <p>I'm creating a file-based Octree of a Point Cloud in order to manage filters on really big file (that can't be stored in ram). The bottleneck of this method, so far, is the I/O of the leaves (because I often have to write, rewrite files and read files ...)<br>
  So I would like to use memory mapped file technique to make it faster, and I heard about Boost.<br>
  But when I search for tutorials, I have seen 2 techniques :<br>
  One use <code>#include &lt;boost/iostreams/device/mapped_file.hpp&gt;</code><br>
  and the other
  <code>#include &lt;boost/interprocess/file_mapping.hpp&gt;</code>.  </p>
  
  <p>In my casae, I will have to write really often entires vectors of 3D points in file, then get all informations in these files and recreate vectors from them. A lot of I/O operation with probably a lot of files.<br>
  I was wondering which one I have to use? In which case I have to use one instead of the other? </p>
  
  <p>Thanks!</p>
  
  <p>P.S : <a href="https://stackoverflow.com/questions/2531652/is-there-a-difference-between-boost-iostream-mapped-file-and-boost-interprocess">Is there a difference between boost iostream mapped file and boost interprocess mapped file?</a> I have seen this post, but it doesn't help me for my particular problem.</p>