“libc ++ abi.dylib：以std :: invalid_argument类型的未捕获异常终止：stoi：no conversion”

Question

我一直得到“libc ++ abi.dylib：以std :: invalid_argument：stoi：no conversion”的未捕获异常终止，最后用于“Total”计算。请建议具体更正。不知道如何纠正它。

int main() {

    vector<Record> records; //Vector of type Record to hold each "line" 
    from the input file
    string database;


    /**
     * Puts each line of the input file into the records vector
     */
    string line;
    string department;
    string item_code;
    int quanity;
    double cost;
    while(!ifs.eof() && ifs.is_open()) {

        records.push_back(newRecord(ifs));
    }

    ifs.close(); //Close the stream


    sort(records.begin(),records.end(), sortByItem_code);
    stable_sort(records.begin(),records.end(), sortByDepartment);

    custom mycustom =custom(records);

    vector<Record> customRecords = mycustom.customRecords(true);

    ofstream output("/Users/ziyingyu/Downloads/new_" + database);

    string newifs;
    cout<<fixed;
    cout<<setprecision(2);
    std::string::size_type sz;

    output.open("/Users/ziyingyu/Downloads/new_" + database);
        for (int i = 0; i < customRecords.size(); ++i)
          {
                /**
            *go through each record of our clean records file
            */
            output << i << "," << customRecords[i]<<endl;
            cout << i << "," << customRecords[i]<<endl;
          }
        output.close();

     output.open("/Users/ziyingyu/Downloads/new_" + database);
     for(int i = 0; i < customRecords.size(); i++)
        {
            cout<<left<<setw(15)<<customRecords[i].department;
            cout<<left<<setw(17)<<customRecords[i].item_code;
            cout<<left<<setw(13)<<customRecords[i].quantity;
            cout<<left<<setw(15)<<customRecords[i].cost;
            cout<<left<<setw(15)
                <<double(std::stoi(customRecords[i].quantity, 
             &sz)*std::stod(customRecords[i].cost, &sz))<<endl;
            cout<<endl;
        }

    return 0;
 }