| Macros by Category | Revision History | 
   _AC_C_IFDEF(MACRO-NAME, ACTION-IF-DEF, ACTION-IF-NOT-DEF)
  
Check for the definition of macro MACRO-NAME using the current language's compiler.
http://autoconf-archive.cryp.to/_ac_c_ifdef.m4
Copyright © 2008 Ludovic Courtès <ludo@chbouib.org>
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