I have to configure my compilation depending on build hosts. Windows and Linux are easy and I have access to the build hosts to test it myself anyway.
What I have so far completely failed to find are the values of $(OS) and, just to check my expectations, $(OSPLAT). I assume OSPLAT to be X86 on x86 machines, similar to other QNX supported SDP packages
If anyone has access to a QNX/Neutrino system with installed QNX SDP, the Jam script below can produce the result:
Echo $(OS) $(OSPLAT) ;
I had a look at Jam source and it seems that depending on the platform version it is either QNX or QNXNTO. See jam.h for more details and OSPLAT values.