Modifies orig to cover only the text after split_index, and
returns a new item that covers the text before split_index that
used to be in orig. You can think of split_index as the length of
the returned item. split_index may not be 0, and it may not be
greater than or equal to the length of orig (that is, there must
be at least one byte assigned to each item, you can't create a
zero-length item).
This function is similar in function to pango_item_split() (and uses
it internally.)
Modifies orig to cover only the text after split_index, and returns a new item that covers the text before split_index that used to be in orig. You can think of split_index as the length of the returned item. split_index may not be 0, and it may not be greater than or equal to the length of orig (that is, there must be at least one byte assigned to each item, you can't create a zero-length item).
This function is similar in function to pango_item_split() (and uses it internally.)