30 Input/output library [input.output]

30.5 Iostreams base classes [iostreams.base]

30.5.3 Class ios_­base [ios.base]

30.5.3.3 ios_­base functions [ios.base.locales]

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.
Returns: The previous value of getloc().
Postconditions: loc == getloc().
locale getloc() const;
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.