Hi Dave, Here are some defines you could test against which show up for C++ and are absent for C: __GNUG__ __GXX_WEAK__ __cplusplus Note that the gcc compiler can compile either C or C++ code. And the g++ compiler can compile either C or C++ code. (As I understand it, neither gcc or g++ is a compiler per se. Rather, they are toolchain drivers, which invoke the compiler.) You can also explicitly tell the toolchain driver that the code is C or C++, using -x c and -x c++ (amongst others, see 'man gcc'), and which particular standard to adhere to by -std=<standard> (see 'man gcc'). To view the predefined preprocessor defines that are provided, for example: echo '' | g++ -std=c++98 -ansi -pedantic -E -dM -x c++ - | sort Change the parameters a bit as desired, and save the outputs, and diff them to see the deltas. Sincerely, --Eljay
