#include <ios>

#include <iostream>

#include <sstream>

#include <stdexcept>

{

struct TestEnum

};

// An input operator a-la-boost date_time. This input operator will catch

// anything and rethrow if the exception mask for the input stream is set to

// throw on failure.

std::istream& operator>>(std::istream& in, TestEnum::type& value)

{

try {

std::string raw;

if (not (in >> raw)) { return in; }

if (raw == "Zero") { value = TestEnum::Zero; return in; }

if (raw == "One") { value = TestEnum::One; return in; }

// The boost input operator uses it's own facet for input which can

// throw, so we simulate something failing by just throwing an exception

// directly.

std::ios_base::failure failz("<input failure>");

std::cout

<< "Throwing std::ios_base::failure: |" << failz.what() << "|..."

<< std::endl;

throw failz;

}

catch (...) {

const std::ios_base::iostate exception_mask = in.exceptions();

if (std::ios_base::failbit & exception_mask) {

try { in.setstate(std::ios_base::failbit); }

catch(std::ios_base::failure&) {}

throw; // rethrow original exception

}

else {

in.setstate(std::ios_base::failbit);

}

}

return in;

}

}

int main()

}