Cxx.jl and -D flags

So I am trying to use Cxx.jl to wrap a C++ library but I’m coming across some issues. As a start, I am converting some C++ code to Cxx.jl. And when I compile the C++, I need to pass a -D flag in order to turn on some options.

E.g. g++ classification.cpp -DUSE_CUDNN -I/blah/ -lblah

But I don’t know how to turn on this option for Cxx.jl. Is this possible to do in Cxx.jl? And it’s not, is there any alternative ways of doing this? Thanks.

Okay, I figured it out. I had to both pass the flags while compiling the original library and set cxx" #define USE_CUDNN " in my library too.