Catching an exception for input and output file - c++

Question

I open two files, one input and one output. I'd like to handle exceptions for both of them, so by looking at some examples, I made this:
std::ifstream readFile;
readFile.exceptions (std::ifstream::failbit | std::ifstream::badbit);
//set the flags for stream bits that indicate failure if ON
std::ofstream writeFile;
writeFile.exceptions (std::ifstream::failbit | std::ifstream::badbit);
try{
readFile.open(inputFileName);
writeFile.open(outputFileName);
function(readFile, writeFile);
readFile.close();
writeFile.close();
}
catch(std::ifstream::failure &readErr) {
std::cerr << "\n\nException occured when reading a file\n"
<< readErr.what()
<< std::endl;
return -1;
}
catch(std::ofstream::failure &writeErr) {
std::cerr << "\n\nException occured when writing to a file\n"
<< writeErr.what()
<< std::endl;
return -1;
}
This seems like a reasonable solution, but I get a warning:
warning: exception of type 'std::ios_base::failure' will be caught [enabled by default]
catch(std::ofstream::failure &writeErr) {
^
The code does it's thing, but I'm still interested in improving my code. Where have I wronged?

Answer 1

No you can't. The typedef of std::ifstream::failure and std::ofstream::failure are both defined to be std::ios_base::failure.
The best thing you could do is wrap the individual calls with try-catch:
try
{
readFile.open(inputFileName);
}
catch(std::ifstream::failure &readErr)
{
}
try
{
writeFile.open(outputFileName);
}
catch(std::ofstream::failure &writeErr)
{
}
Or check the state of the streams individually in the catch block to see who failed.

Answer 2

The only way to handle exceptions from the two files separately would be to catch the exception and then check the failbit on the streams to determine which of them that failed:
try
{
readFile.open(inputFileName);
writeFile.open(outputFileName);
function(readFile, writeFile);
readFile.close();
writeFile.close();
}
catch (const std::ios_base::failure &err)
{
if (readFile.fail())
{
std::cerr << "\n\nException occured when reading a file\n"
<< readErr.what()
<< std::endl;
}
if (writeFile.fail())
{
std::cerr << "\n\nException occured when writing to a file\n"
<< writeErr.what()
<< std::endl;
}
return -1;
}