[解決済み] C++ Void関数とファイルストリームエラー

質問

入力ファイルを受け取り、それを整理していくつかの値を計算するコードを書こうとしています。しかし、getName関数で問題を抱えています。getメンバ関数を使用して、参照パラメータで呼び出したものに姓と名を割り当て、-1が読み込まれた場合は入力ファイルの文字を合計することになっています。以下は、このコードに対するエラー引数です。

main.cpp:7:14: error: variable or field 'getName' declared void
main.cpp:7:14: error: 'ifstream' was not declared in this scope
main.cpp:7:24: error: 'shoppingCartInput' was not declared in this scope
main.cpp:7:43: error: 'string' was not declared in this scope
main.cpp:7:51: error: 'firstname' was not declared in this scope
main.cpp:7:62: error: 'string' was not declared in this scope
main.cpp:7:70: error: 'lastname' was not declared in this scope
main.cpp:102:50: error: 'getName' was not declared in this scope

以下はそのコードです。

#include <iostream>
#include <string>
#include <fstream>
#include <cstdlib>
#include <cctype>

void getName(ifstream& shoppingCartInput, string& firstname, string& lastname);

using namespace std;
int main()
{
    // declerations
    string infile_name = "";
    string shopper = "";
    string firstname ="";
    string lastname = "";
    int quantity;
    double price = 0.0, leastExpPrice = 0, mostExpPrice = 0;
    string item, leastExpItem, mostExpItem;
    double totalCost = 0.0;
    //1) Open Your File
    cout << "please enter the name of the input file:";
    cin >> infile_name;
    cout << "\n";
    ifstream shoppingCartInput;
    ofstream shoppingCartOutput;
    shoppingCartInput.open(infile_name.c_str());
    if(shoppingCartInput.fail( )) {
    cout << "Input file opening failed.\n";
    exit(1);
    }
    shoppingCartOutput.open("output_file.dat");
    if(shoppingCartOutput.fail( )) {
        cout << "Output file opening failed.\n";
        exit(1);
    }
    //2) Read the first line
    shoppingCartInput >> quantity >> price >> item;
    //printing the line to the console (properly organized)
    shoppingCartOutput.setf(ios::fixed);
    shoppingCartOutput.setf(ios::showpoint);
    shoppingCartOutput.setf(ios::left);
    shoppingCartOutput.width(15);
    shoppingCartOutput << item << " ";
    shoppingCartOutput.setf(ios::right);
    shoppingCartOutput.width(3);
    shoppingCartOutput << quantity << " ";
    shoppingCartOutput.setf(ios::right);
    shoppingCartOutput.width(6);
    shoppingCartOutput.precision(2);
    shoppingCartOutput << price << " ";
    shoppingCartOutput.setf(ios::right);
    shoppingCartOutput.width(7);
    shoppingCartOutput.precision(2);
    shoppingCartOutput << (quantity * price) << endl;
    //set it as the most expensive
    //set it as the least expensive
    leastExpPrice = price;
    leastExpItem = item;
    mostExpPrice = price;
    mostExpItem=item;
    //initialize total cost to get the cost of the first line of data
    totalCost = (quantity * price);
    //3) Read until the end of the file
    while(!(shoppingCartInput.eof())) {
        while(quantity != -1) {
            shoppingCartInput >> quantity >> price >> item;
            //printing the line to the console (properly organized)
            shoppingCartOutput.setf(ios::fixed);
            shoppingCartOutput.unsetf(ios::right);
            shoppingCartOutput.setf(ios::showpoint);
            shoppingCartOutput.setf(ios::left);
            shoppingCartOutput.width(15);
            shoppingCartOutput << item << " ";
            shoppingCartOutput.setf(ios::right);
            shoppingCartOutput.width(3);
            shoppingCartOutput << quantity << " ";
            shoppingCartOutput.setf(ios::right);
            shoppingCartOutput.width(6);
            shoppingCartOutput.precision(2);
            shoppingCartOutput << price << " ";
            shoppingCartOutput.setf(ios::right);
            shoppingCartOutput.width(7);
            shoppingCartOutput.precision(2);
            shoppingCartOutput << (quantity * price) << endl;
            if(price < leastExpPrice) {
                leastExpPrice = price;
                leastExpItem = item;
            }
            if(price > mostExpPrice) {
                mostExpPrice = price;
                mostExpItem=item;
            }
            totalCost += (quantity * price);
        }
        if (quantity == (-1)) {
            string first = "";
            string last = "";
            getName(shoppingCartInput, firstname, lastname);
            shopper = firstname + " " + lastname;
            shoppingCartOutput << "\ncheapest item = " << leastExpItem <<
                        endl;
            shoppingCartOutput << "most expensive item = " << mostExpIte <<
                        endl;
            shoppingCartOutput << "total cost = " << totalCost << endl;
            shoppingCartOutput.unsetf(ios::right);
            shoppingCartOutput.setf(ios::left);
            shoppingCartOutput << "shopper = " << shopper;
        }
    }
    shoppingCartInput.close();
    shoppingCartOutput.close();
    return 0;
}

void getName(ifstream& shoppingCartInput, std::string& firstname, std::string&
lastname)
{
    char letter;
    do {
         shoppingCartInput.get(letter);
         firstname += letter - 1;
    } while (letter != ',');

    do {
        shoppingCartInput.get(letter);
        lastname += letter;
    } while (letter != '\n' || letter != 'r');
}

解決方法は？

を変更します。

void getName(ifstream& shoppingCartInput, string& firstname, string& lastname);
using namespace std;

になります。

using namespace std;
void getName(ifstream& shoppingCartInput, string& firstname, string& lastname);