vector_wrapper.hpp

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

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); }

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