+
+/* Converts the wide character wc into the corresponding multibyte character
+ sequence (including shift sequences). If s is not a null pointer, the
+ multibyte sequence (at most MB_CUR_MAX characters) is stored at that
+ location. If wc is a null character, a null byte is stored, preceded by
+ any shift sequence needed to restore the initial shift state, and the
+ function is left in the initial conversion state.
+ Returns the number of bytes in the generated multibyte character sequence.
+ If wc does not correspond to a valid multibyte character, returns -1.
+ In no case will the returned value be greater than MB_CUR_MAX.
+ If s is a null pointer, returns nonzero if multibyte encodings in the
+ current locale are stateful, and zero otherwise.
+*/