Function xgboost_sys::XGDMatrixSaveBinary

pub unsafe extern "C" fn XGDMatrixSaveBinary(
    handle: DMatrixHandle, 
    fname: *const c_char, 
    silent: c_int
) -> c_int

\brief load a data matrix into binary file \param handle a instance of data matrix \param fname file name \param silent print statistics when saving \return 0 when success, -1 when failure happens