title: Why should I use "use, only" in Fortran
body: <p>In python a statement like this:</p>
  
  <pre><code>from module import function354
  </code></pre>
  
  <p>makes sense, because Python is an interpreter language and I don't want python to load all 353 other functions.</p>
  
  <p>Fortran has a similar construct:</p>
  
  <pre><code>use module, only : function354
  </code></pre>
  
  <p>Why would I use this? The compiler creates a *.mod file anyway, compiling all function. Is there any performance advantage (in compile or run time) if I specify an <code>only</code>-statement?</p>
  
  <p>I can see that it might be helpful to avoid naming conflict, but other than that I don't really see the point.</p>