public void set_line_offset (int char_on_line)
Moves this within a line, to a new character (not byte) offset.
The given character offset must be less than or equal to the number of characters in the line; if equal, this moves to the start of the next line. See [method@Gtk.TextIter.set_line_index] if you have a byte index rather than a character offset.
a character offset relative to the start of this’s current line