Try-Catch Block For C++ File-IO Errors Not Working

I'm very new to the world of C++ error handling, but I was told here:
Checking for file existence in C++

...that the best way to checks for file existence was with a try-catch block. From my limited knowledge on the topic, this sounds like sound advice. I located this snippet of code:
http://www.java2s.com/Tutorial/Cpp/0240__File-Stream/Readafileintrycatchblock.htm

#include 
#include 
using namespace std;

int main () 
{
  try{
      char buffer[256];
      ifstream myfile ("test.txt");

      while (! myfile.eof() )
      {
        myfile.getline (buffer,100);
        cout << buffer << endl;
      }
  }catch(...){
     cout << "There was an error !\n";
  }
  return 0;
}

...but when I compile it using

g++ -Wall -pedantic -o test_prog main.cc

And run the program in a directory where test.txt does not exist, the prog keeps spitting out empty lines to the terminal. Can anyone figure out why?

Also is this a good way to check for file existence for a file you actually want to open and read from (versus just something where your indexing a bunch of files and checking them over)?

Thanks!