How can I convert an int to a string in C++11 without using to_string or stoi?

Question

I know it sounds stupid, but I'm using MinGW32 on Windows7, and "to_string was not declared in this scope." It's an actual GCC Bug, and I've followed these instructions and they did not work. So, how can I convert an int to a string in C++11 without using to_string or stoi? (Also, I have the -std=c++11 flag enabled).

Answer 1

Its not the fastest method but you can do this:

#include <string>
#include <sstream>
#include <iostream>

template<typename ValueType>
std::string stringulate(ValueType v)
{
    std::ostringstream oss;
    oss << v;
    return oss.str();
}

int main()
{
    std::cout << ("string value: " + stringulate(5.98)) << '\n';
}

Answer 2

I'd like to answer it differently: just get mingw-w64.

Seriously, MinGW32 is just so full of issues it's not even funny:

• http://sourceforge.net/p/mingw/bugs/1578/
• http://sourceforge.net/p/mingw/mailman/message/23108552/
• wWinmain, Unicode, and Mingw

With MinGW-w64 you get for free:

• support for Windows Unicode entry point (wmain/wWinMain)
• better C99 support
• better C++11 support (as you see in your question!)
• large file support
• support for C++11 threads
• support for Windows 64 bit
• cross compiling! so you can work on your Windows app on your favorite platform.

Answer 3

You can use stringstream.

#include <string>
#include <sstream>
#include <iostream>
using namespace std;

int main() {
    int num = 12345;
    stringstream ss;
    ss << num;
    string str;
    ss >> str;
    cout << str << endl;
    return 0;
}

Answer 4

You could roll your own function to do it.

std::string convert_int_to_string (int x) {
  if ( x < 0 )
    return std::string("-") + convert_int_to_string(-x);
  if ( x < 10 )
    return std::string(1, x + '0');
  return convert_int_to_string(x/10) + convert_int_to_string(x%10);
}