/// get offset of this cursor slice relative to our upper left corner
void cursorPos(BufferView const & bv, CursorSlice const & sl,
bool boundary, int & x, int & y) const;
/// get offset of this cursor slice relative to our upper left corner
void cursorPos(BufferView const & bv, CursorSlice const & sl,
bool boundary, int & x, int & y) const;