what does "@SOME_VALUE@" mean in C++ header -
    i've seen in c++ headers:   #define value_a @value_a@   or   #if @value_a@ ... #endif   so, tell me @@  mean?   thanks lot.          probably got source code other source (not yours) , not someheader.h  someheader.h.in   all @something@  tags substituted configure  script on program configuration.  configure  , proper header file @something@  substituted.   some reading autoconf  info documentation make light darkness.