Indexed for each in C++

for_indexed.hpp

#ifndef FOR_INDEXED_LIB
#define FOR_INDEXED_LIB

// Usage: for_indexed(begin, end, [](auto &e, auto i) { ~: });

template<class ForwardIterator, class Func>
void for_indexed(ForwardIterator head, ForwardIterator tail, Func func) {
  size_t i = 0;
  for (auto it = head; it != tail; ++it, ++i) func(*it, i);
}

#endif // FOR_INDEXED_LIB