iterator.cc

#include <iostream>
#include <vector>

template<class It> using Value = typename std::iterator_traits<It>::value_type;

template<class It> Value<It> sum(It begin, It end) {
  Value<It> res = 0;
  while (begin != end)
    res += *begin++;
  return res;
}

int main(void) {
  int a[] = {0, 1, 2, 3, 4, 5};

  size_t size = sizeof(a) / sizeof(a[0]);
  std::cout << sum(a, a + size) << std::endl;

  std::vector<int> v(a, a + size);
  std::cout << sum(v.begin(), v.end()) << std::endl;
}