public member type
Event callback function type
Type for callback functions registered with member register_callback.
It is defined as a member type of ios_base as:
typedef void (*event_callback) (event ev, ios_base& obj, int index);
Therefore it is a function returning no value and having taking three arguments:
- An object of enum member type event. When the callback function is called, this is set to one of the three possible values to indicate what type of event triggered the function call.
- When the callback function is called, this is a reference to the stream object on which the even is triggered (
- When the callback function is called, this is set to the same value used as index argument when the function was registered with member register_callback.