I'm Looking for an implementation of the IAPWS-IF97 water properties on C/C++. I'm aware of the library freesteam. However freesteam does not include all the properties I'm looking for. Particularly I need differential properties like dh/dp, dv/dp and in certain regions. I use a similar implementation for Octave/Matlab and I would also like to have it in C/C++.
If you could only use Java, our open source IF97 library provides partial derivatives, see: www.hummeling.com/IF97
And it can be used for proprietary software as well.