codecvt::do_in

virtual result do_in(State state&,
    const To *first1, const To *last1, const To *next1,
    From *first2, From *last2, From *next2);

The protected virtual member function endeavors to convert the source sequence at [first1, last1) to a destination sequence that it stores within [first2, last2). It always stores in next1 a pointer to the first unconverted element in the source sequence, and it always stores in next2 a pointer to the first unaltered element in the destination sequence.

state must represent the initial conversion state at the beginning of a new source sequence. The function alters its stored value, as needed, to reflect the current state of a successful conversion. Its stored value is otherwise unspecified.

The function returns:

• codecvt_base::error if the source sequence is ill-formed
• codecvt_base::noconv if the function performs no conversion
• codecvt_base::ok if the conversion succeeds
• codecvt_base::partial if the source is insufficient, or if the destination is not large enough, for the conversion to succeed

The template version always returns noconv.