std::ios_base::event
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                    | enum event {erase_event, imbue_event, copyfmt_event}; | ||
Specifies the event type which is passed to functions registered by register_callback() on specific events. The following constants are defined:
| Constant | Explanation | 
| erase_event | issued on ~ios_base() or basic_ios::copyfmt() (before the copy of members takes place) | 
| imbue_event | issued on imbue() | 
| copyfmt_event | issued on basic_ios::copyfmt() (after the copy of members takes place, but before the exception settings are copied) | 
Example
| This section is incomplete Reason: no example |