what does this declaration mean? exception() throw()

Question

std::exception class is defined as follows

exception() throw() { }
virtual ~exception() throw();
virtual const char* what() const throw();

Answer 1

This is called a throw specification. It defines which exceptions (if any) can be thrown from the function.

These sound great in theory, but there are issues with using them.

A good discussion about this can be found at this SO question.