title: How to create a Log in C++?
body: <p>I want to print lots of debug log prints in C++. Is there a built-in library that will allow me to turn on/off these prints without commenting them out as I do today (i.e., let the user use a <code>-print_log</code>/<code>-debug</code> flag)?</p>
  
  <p><strong>EDIT</strong>: third party loggers will be welcomed.</p>
  
  <p>Please include a short example of how to do this.</p>