locale imbue(const locale& loc);

Effects: Calls each registered callback pair (fn, idx) ([ios.base.callback]) as (*fn)(imbue_event, *this, idx) at such a time that a call to ios_base​::​getloc() from within fn returns the new locale value loc.

Postconditions: loc == getloc().

Returns: The previous value of getloc().

Returns: If no locale has been imbued, a copy of the global C++ locale, locale(), in effect at the time of construction.

Otherwise, returns the imbued locale, to be used to perform locale-dependent input and output operations.