cpp/error/uncaught exception

@1@ Detects if the current thread has a live exception object, that is, an exception has been thrown or rethrown and not yet entered a matching catch clause, std or std. In other words, detects if stack unwinding is currently in progress. @2@ Detects how many exceptions in the current thread have been thrown or rethrown and not yet entered their matching catch clauses.

Sometimes it's safe to throw an exception even while. For example, if stack unwinding causes an object to be destructed, the destructor for that object could run code that throws an exception as long as the exception is caught by some catch block before escaping the destructor.

Parameters
(none)

Return value
@1@ if stack unwinding is currently in progress in this thread,  otherwise. @2@ The number of uncaught exception objects in the current thread.