[[noreturn]] void terminate() noexcept;
Remarks: Called by the implementation when exception handling must be abandoned for any of several reasons ([except.terminate]). May also be called directly by the program.
Effects: Calls a terminate_handler function. It is unspecified which terminate_handler function will be called if an exception is active during a call to set_terminate. Otherwise calls the current terminate_handler function. [ Note: A default terminate_handler is always considered a callable handler in this context. — end note ]