vector_wrapper.hpp

class VectorWrapperBase {
  public:
    virtual ~VectorWrapperBase() {}
    virtual void reserve(unsigned int n) = 0;
    virtual VectorWrapperBase* clone() const = 0;
};

inline VectorWrapperBase* new_clone(const VectorWrapperBase& a) {
  return a.clone();
}

template <typename T>
class VectorWrapper: public VectorWrapperBase {
  public:
    typedef T data_type;
    typedef std::vector<T> vector_type;
    void reserve(unsigned int n) { v_.reserve(n); }
    VectorWrapper<T>* clone() const { return new VectorWrapper<T>(*this); }

  private:
    std::vector<T> v_;
};