Not callable from C++ without wrappers

[titinko]

I tried to use this library from C++ and ended up needing to add an extern "C" wrapper around the method headers in pyin.h to make it callable by C++. These wrappers could be built into pyin.h to make things easier on the next C++ coder who uses this library:

#ifdef __cplusplus
extern "C" {
#endif

// The method headers that need to be wrapped.
pyin_config pyin_init(int nhop);
int pyin_trange(int nq, FP_TYPE fmin, FP_TYPE fmax);
FP_TYPE* pyin_analyze(pyin_config param, FP_TYPE* x, int nx, FP_TYPE fs, int* nfrm);

#ifdef __cplusplus
}
#endif

See https://stackoverflow.com/questions/1041866/what-is-the-effect-of-extern-c-in-c for more context on this issue.