template<typename T>
T SumArray(T const *const array, int count, int start = 0)
{
    T sum = T();
    while(count-- > 0) sum += array[start++];
    while(++count < 0) sum -= array[--start];
    return sum;
}

template<typename T>
T SumArray(T const *const *const array, int count0, int count1, int start0 = 0, int start1 = 0)
{
    T sum = T();
    while(count0-- > 0) sum += SumArray<T>(array[start0++], count1, start1);
    while(++count0 < 0) sum -= SumArray<T>(array[--start0], count1, start1);
    return sum;
}

int f(int* array, int size_x, int size_y)
{
  // ..
  for (int i = 0; i < size_x; ++i)
    for (int j = 0; j < size_y; ++j)
      //..
    }
  }
}