message: elle.compiler: safety belts in macros
diff: #if defined __GNUC__ && !defined __clang__
  # define GCC_VERSION_LTE(Major, Minor) \
  - (__GNUC__) < Major || (__GNUC__) == Major && (__GNUC_MINOR__) <= Minor
  + ((__GNUC__) < (Major) \
  + || (__GNUC__) == (Major) && (__GNUC_MINOR__) <= (Minor))
  #else
  # define GCC_VERSION_LTE(Major, Minor) 0
  #endif
  