Does catch (…) work on throw; with no object?

问题:

What does C++ standard say should happen for the following code when there is no pending exception being processed higher up the stack?

try {
  throw;
} catch (...) {
  cerr << "Caught exception." << endl;
}

Will the throw with no object be caught or not?

回答1:

From the 2003 C++ Standard §15.1[except.throw]/8:

If no exception is presently being handled, executing a throw-expression with no operand calls terminate().

So, in your example, since no exception is currently being handled, nothing is thrown and instead terminate() is called. Since terminate() does not return, your catch block will never be entered.