Example 2: Adapting this class with sequence_range will give you compile errors.

class ro_vector
{
public:
  typedef int       value_type;
  typedef int const &const_reference;
  typedef int const *const_iterator;
public:
  ... constructors
public: // begin()/end() - no mutating forms!
  const_iterator begin() const;
  const_iterator end() const;
private: // Internals
  ... 
};