[Fontconfig] how to enforce scalable fonts

[Werner LEMBERG]

Within an application, how can I enforce fontconfig to return scalable
fonts only?  In other words, I want the equivalent to

  <fontconfig>
  <selectfont>
   <rejectfont>
   <pattern>
    <patelt name="scalable"><bool>false</bool></patelt>
   </pattern>

but without adding that to a local fontconfig config file.


    Werner