Thread: "Bad Bit"

The badbit is set after a system failure affecting the stream. It's not easy to deliberatly provoke it. It's usually not possible to recover from it, so this is an error that should originate a program failure and termination.

Write your custom stream insertion/extraction operator and throw an exception from that:

Code:

#include <iostream>
#include <stdexcept>

class dummy {};

ostream & operator << (ostream &, const dummy &)
{
  throw std::runtime_error("gotcha")<
}

int main()
{
  try {
    std::cout << dummy();
  } catch(std::runtime_error &) {
  }
  bool b = std::cout.fail();
  std::cout.clear();
  std::cout << "Failbit: " << b << "\n";
}