title: What does 'REF' mean in glibc vfprintf.c?
body: <p>I'm fairly (very) new to c++/ linux and am looking through the vfprintf function in glibc. It includes many uses of REF (...), which I'm assuming is a macro, but I can't find its definition anywhere. I've searched the file itself as well as all the included files.</p>
  
  <p>Is it a macro? If so, where is its definition? Also is there a better way to find the definition of macros than searching all the included files one by one?</p>