fstream error in C++

Question

I really need your help. It seems that I can't do file manipulation in C++. I used fstream to do some file manipulation but when I compile it, an error appears that say:

|63|error: no matching function for call to 'std::basic_fstream<char>::open(std::string&, const openmode&)'|

What is the mistake I've done?

Here is part of the source code:

#include<stdio.h>
#include<iostream>
#include<fstream>
#include<string>    

using namespace std;

inline int exports()
{
string fdir;
// Export Tiled Map
cout << "File to export (include the directory of the file): ";
cin >> fdir;
fstream fp; // File for the map
fp.open(fdir, ios::app);
if (!fp.is_open())
    cerr << "File not found. Check the file a file manager if it exists.";
else
{
    string creator, map_name, date;
    cout << "Creator's name: ";
    cin >> creator;
    cout << "\nMap name: ";
    cin >> map_name;
    cout << "\nDate map Created: ";
    cin >> date;
    fp << "<tresmarck valid='true' creator='"+ creator +"' map='"+ map_name +"'   date='"+ date +"'></tresmarck>" << endl;
    fp.close();
    cout << "\nCongratulations! You just made your map. Now send it over to [email protected] for proper signing. We will also ask you questions. Thank you.";
}
return 0;
}

Answer 1

The fstream::open() that accepts std::string type as the file name was added in C++11. Either compile with -std=c++11 flag or use fdir.c_str() as the argument (to pass const char* instead).

Note that the fstream() constructor can open the file if provided with the file name, which would eliminate the call to fp.open():

if (std::cin >> fdir)
{
    std::fstream fp(fdir, std::ios::app); // c++11
    // std::fstream fp(fdir.c_str(), std::ios::app); // c++03 (and c++11).
    if (!fp.is_open())
    {
    }
    else
    {
    }
}

Answer 2

You need to enable C++11 mode for std::basic_fstream<char>::open(std::string&, const openmode&) overload to be avaliable.

Pass one of these to gcc:

-std=c++11 or -std=c++0x

Prior to C++11, istream::open functions took only C-strings. (You can call it by saying fp.open(fdir.c_str(), ios::app);)