title: QLocale, what is the scope of the global QLocale::setDefault()?
body: <p>Problem: </p>
  
  <ul>
  <li><p>I have a QT based multiplatform (win,mac,*nix) application that parses ascii files containing decimal numbers. </p></li>
  <li><p>parsing is done using a variety of different code pieces that use anything from qt string stuff, c++ stdin, oldstyle scanf, etc.</p></li>
  <li><p>ascii files have always the '.' (dot) as separated decimal (e.g. in the file to be parsed 1/10 is written 0.1 as standard in many countries).</p></li>
  <li><p>people using the application within a OS localized for using comma separated decimal encounter a lot of problems (e.g. for french users scanf expect to find 0,1 as a valid textual representation of 1/10 and if they find 0.1 scanf will parse it as 0)</p></li>
  </ul>
  
  <p>How can I be sure that the OS Locale indication of how decimal point has to be written is always ignored?</p>
  
  <p>Is it safe assuming that adding</p>
  
  <pre><code> QLocale::setDefault(QLocale(QLocale::English,QLocale::UnitedStates));
  </code></pre>
  
  <p>is enough to get rid of all these problems? 
  Any suggestion for portable ways of setting the locale globally?</p>