How do you know if a C++ fstream operation failed?

[_Elixia_]

say you have the following code:

fstream mystream;
if (mystream.is_open())
{
   mystream << 55;
   mystream.close();
}

How would I know if the "mystream << 55" actually worked and wrote the 55 to the file? The fstream part of C++ seems heavily documented in the usage of what you can do, but no ones seems interested in error handling.

[gamer4life687]

Salem is correct of course.

#include <iostream>
#include <fstream>
using namespace std;

int main()
{
	fstream mystream;

	mystream.is_open();
	if (mystream.fail())
	{
		cout << "Error opening file"<<endl;

	}
	mystream << 55;
	mystream.close();
	return 0;
}

[Zach L.]

Actually, you want to test fail() after the write command.

[Eibro]

Or just put the write operation in an if statement:

if (!(WriteFile << Something))
{
     cerr << "Failed write!\n";
}

[Korhedron]

Here it is again, "cerr"... Can you explain the difference between this and "cout", and if there are any like this ?

[Wledge]

>>Here it is again, "cerr"
Click.