How to forbid file replacing in fstream library for C++

[rizaado]

How to forbid file replacing in fstream library for C++?

#include <iostream>
#include <fstream>

using namespace std;

int main()
{
  ofstream myfile;
  myfile.open ("example.txt");
  myfile << "Writing this to a file.\n";
  myfile.close();
  cin.get;
  return 0;
};

[rizaado]

I mean when the code is executed. How to forbid replacing the file("example.txt") as I executed the code again.

[JLBorges]

See http://stdcxx.apache.org/doc/stdlibug/30-3.html

[rizaado]

I am confused, please take me the mode flag which forbid the file replacing.

[JLBorges]

// open the file for reading and writing, fail if file does not exist
std::fstream one( "example.txt", std::ios::in | std::ios::out ) ;

// open an existing file for reading and writing, 
// or create a new file if it does not exist, 
// write always appends to the file
std::fstream one( "example.txt", std::ios::in | std::ios::out | std::ios::app ) ;

[rizaado]

Thank you.