c++ - Ofstream オブジェクトは << 演算子 C++ を使用できません

Question

テキストをファイルに書き込もうとしていますが、ofstream クラスのオブジェクトを定義した後、「;」というエラーが発生します。<< 演算子を使用してファイルに書き込むことはどこでも予想されます。Visual Studio 2012 を使用しています。

これは単純なポート スキャナー (cplusplus リファレンスを使用) であり、write_check 変数は、ログ ファイルが必要かどうかをユーザーに確認します。

#include <iostream>
#include <SFML/Network.hpp>
#include<fstream>


using namespace std;


bool port_open(const string& address, int port)
{
    sf::TcpSocket socket;
    bool open = (socket.connect (sf::IpAddress(address), port)==sf::Socket::Done);
    socket.disconnect();
    return open;
}
int main()
{ string address;
  int port, check, in_port, fin_port;
  char write_check;
  cout<<"Press 1 for single port and 2 to check the range of ports.";
  cin>>check;


  switch(check)
  {case 1:
      {
  cout<<"Enter the ip address of the client: ";
  std::cin>>address;

  cout<<"Enter the port to scan: ";
  cin>>port;

  if(port_open(address, port))
      cout<<"The port "<<port<<" at IP:"<<address<<" is OPEN."<<endl;
  else 
      cout<<"The port "<<port<<" at IP:"<<address<<" is CLOSED.";
  break;
      }

  case 2:
      {
       cout<<"Enter the ip address of the client: ";
       cin>>address;

  cout<<"Enter the port from where scanning has to be started ";
  cin>>in_port;
  cout<<"Enter the port upto which scanning has to be done. ";
  cin>>fin_port;

  cout<<"Would you like to have the log in text file? y/n";
  cin>>write_check;

  if (write_check=='y')
     std::ofstream tofile ("Log.txt");



  for(int j=in_port; j<=fin_port; j++)
  {
      cout<<"Scanning port "<<j<<" on IP "<<address<<"...\n";
    if (write_check=='y')
      tofile <<"Scanning port "<<j<<" on IP "<<address<<"...\n";  //ERROR a ';' is expected (after tofile)

   if(port_open(address, j))
      {
          cout<<" OPEN."<<endl;
       if (write_check=='y')
            tofile<<"OPEN."<<endl;     //ERROR a ';' is expected (after tofile)
   }
  else 
     {
         cout<<" CLOSED."<<endl;
      if (write_check=='y')
          tofile<<"CLOSED."<<endl;       //ERROR a ';' is expected (after tofile)
     }
   }
  break;}
  }

  system("pause");
  return 0;
}