const std::vector<float> &get_data() const { return data; }
const float *operator[](unsigned i) const { return &data[0]+i*stride; }
const std::vector<float> &get_data() const { return data; }
const float *operator[](unsigned i) const { return &data[0]+i*stride; }
private:
static void apply_arrays(const std::vector<Array> *, const std::vector<Array> *, const float *, unsigned);
private:
static void apply_arrays(const std::vector<Array> *, const std::vector<Array> *, const float *, unsigned);