Question

We have a project that’s using many C++11 facilities, and we thought about this trick to make it compile on C++03.

#ifndef USE_CPP0X
#    define override
#endif

As far as I know it’s forbidden to define C++ keywords, so is this legal?

Answer 1

It is somewhat frowned upon, but it’s certainly possible. A better and not so frowned upon variant is to define macros in all large letter, something like

#ifndef USE_CPP0x
#  define OVERRIDE
#else
#  define OVERRIDE override
#endif

Then remember to use OVERRIDE instead of override where wanted.