typedef void (*event_callback)(event type, ios_base& ios, int index);

The type of function callbacks that can be registered using register_callback() to be called on specific events.

type is a value of type ios_base::event which indicates the type of the event that will invoke this callback.

ios refers to the stream object for which the callback is invoked: *this is passed as the argument when callbacks are invoked by std::ios_base and std::basic_ios member functions.

index is the user-provided value passed to register_callback() when registering the function.

See also

copies formatting information
(public member function of std::basic_ios<CharT,Traits>)
sets locale
(public member function)
destructs the object
(virtual public member function)
registers event callback function
(public member function)

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