Some exception classes are designed to be used only as base classes to more specific exceptions, for instance, ``++std::exception++`` (the base class of all standard {cpp} exceptions), ``++std::logic_error++`` or ``++std::runtime_error++``.
Catching such generic exception types is usually a bad idea because it implies that the "catch" block is clever enough to handle any type of exception.
There are cases, though, where you want to catch all exceptions because no exceptions should be allowed to escape the function, and generic ``++catch++`` handlers are excluded from the rule:
Additionally, if the ``++catch++`` handler is throwing an exception (either the same as before, with ``++throw;++`` or a new one that may make more sense to the callers of the function) or is never exiting (because it calls a ``++noreturn++`` function, for instance ``++exit++``), then the accurate type of the exception usually does not matter any longer: this case is excluded too.