Function cnlp_init_solution 

pub unsafe extern "C" fn cnlp_init_solution(
    problem: CNLP_ProblemPtr,
    user_data: CNLP_UserDataPtr,
) -> CNLP_Bool

Initialize the solution vectors in the nlp. Calling this is required before calling cnlp_get_solver_data. This function will call the necessary initialization callbacks provided by the user.