Chapter 8 of "the" book contains two errors.

http://www.gtkmm.org/gtkmm2/docs/tutorial/html/ch08.html#id2834309

  ModelColumns()
    { add(m_col_text); add(m_col_number) }

should be 

  ModelColumns()
    { add(m_col_text); add(m_col_number); }

and in Model Columns 

the object is called refListStore

then in adding rows it is called m_refListStore which is seems what it
should be.