distinguishing octave versions with ifdef

[Xavier Delacour]

I would like to make oct-file plugins that compile properly against
multiple versions of octave, in the face of internal API changes.
Ideally I want something like

#if OCTAVE_API_VERSION >= 37
// use new api
#else
// use old api
#endif

In src/version.h I see

#define OCTAVE_API_VERSION "api-v37"

which is difficult to use from the preprocessor.

Can someone suggest a way to do what I want? (without resorting to
configure magic and generating my own defines, etc).

Thanks,
Xavier