Function SCIPgetNLPVarsData 

pub unsafe extern "C" fn SCIPgetNLPVarsData(
    scip: *mut SCIP,
    vars: *mut *mut *mut SCIP_VAR,
    nvars: *mut c_int,
) -> SCIP_RETCODE

gets current NLP variables along with the current number of NLP variables

@pre This method can be called if SCIP is in one of the following stages: - \ref SCIP_STAGE_INITSOLVE - \ref SCIP_STAGE_SOLVING