31 Input/output library [input.output]

31.6 Stream buffers [stream.buffers]

31.6.3 Class template basic_streambuf [streambuf] Virtual functions [streambuf.virtuals] Locales [streambuf.virt.locales]

void imbue(const locale&);
Effects: Change any translations based on locale.
Remarks: Allows the derived class to be informed of changes in locale at the time they occur.
Between invocations of this function a class derived from streambuf can safely cache results of calls to locale functions and to members of facets so obtained.
Default behavior: Does nothing.