Function GetClassLabelsImpl

catboost/libs/model/model_export/onnx_helpers.cpp:119–147

 */
template <class TLabelContainer>
static void GetClassLabelsImpl(
    const TLabelContainer& classLabels,
    TVector<i64>* classLabelsInt64,
    TVector<TString>* classLabelsString) {

    CB_ENSURE(!classLabels.empty(), "Class labels are missing");

    classLabelsInt64->clear();
    classLabelsString->clear();

    switch (classLabels.begin()->GetType()) {
        case NJson::JSON_INTEGER:
            classLabelsInt64->reserve(classLabels.size());
            for (const NJson::TJsonValue& classLabel : classLabels) {
                classLabelsInt64->push_back(classLabel.GetInteger());
            }
            break;
        case NJson::JSON_DOUBLE:
            CB_ENSURE(false, "ONNX format does not support floating-point labels");
        case NJson::JSON_STRING:
            classLabelsString->reserve(classLabels.size());
            for (const NJson::TJsonValue& classLabel : classLabels) {
                classLabelsString->push_back(NCB::ClassLabelToString(classLabel));
            }
            break;
        default:
            CB_ENSURE(false, "Unexpected label type");
    }
}

// only one of classLabelsInt64 or classLabelsString returned nonempty
static void GetClassLabels(