title: c++ most efficient way to send n chars from ifstream to cout
body: <p>I have an ifstream (a binary file on my disk) that I have read up to some point.
  Next I need to send some pre-determined amount of data from this point of the ifstream directly to cout (I know in advance that they will be ascii chars).
  What is an(/the most) efficient way (in terms of execution time)?</p>
  <p>I have a preference for a solution that works in C++11 or before.</p>