Exception Handling and Opening a File?

Question

Is it possible to use exceptions with file opening as an alternative to using .is_open()?

For example:

ifstream input;  try{   input.open("somefile.txt"); }catch(someException){   //Catch exception here } 

If so, what type is someException?

Answer 1

http://en.cppreference.com/w/cpp/io/basic_ios/exceptions

Also read this answer 11085151 which references this article

// ios::exceptions #include <iostream> #include <fstream> using namespace std;  void do_something_with(char ch) {} // Process the character   int main () {   ifstream file;   file.exceptions ( ifstream::badbit ); // No need to check failbit   try {     file.open ("test.txt");     char ch;     while (file.get(ch)) do_something_with(ch);     // for line-oriented input use file.getline(s)   }   catch (const ifstream::failure& e) {     cout << "Exception opening/reading file";   }    file.close();    return 0; } 

Sample code running on Wandbox

EDIT: catch exceptions by const reference 2145147

EDIT: removed failbit from the exception set. Added URLs to better answers.

Answer 2

From the cppreference.com article on std::ios::exceptions

On failure, the failbit flag is set (which can be checked with member fail), and depending on the value set with exceptions an exception may be thrown.