right usage of std::uncaught_exception in a destructor

Question

There are some articles concluding \"never throw an exception from a destructor\", and \"std::uncaught_exception() is not useful\", for example:

• http://www.got

Answer 1

Herb Sutter is referring to a different issue. He's talking about:

try
{
}
catch (...)
{
    try
    {
        // here, std::uncaught_exception() will return true
        // but it is still safe to throw an exception because
        // we have opened a new try block
    }
    catch (...)
    {
    }
}

So the problem is that if std::uncaught_exception() returns true you don't know for sure whether you can safely throw an exception or not. You end up having to avoid throwing an exception when std::uncaught_exception() returns true just to be safe.