Several vector traversal methods in C ++ 11

Assuming that there is such a vector:

vector<int> line={1,2,3,4,5,6,7,8,9};

Each element in the vector needs to be output, the main function is as follows:

void showvec(const vector<int>& line)
{
}

int main(int argc, char** argv) {
  vector<int> line = {1, 2, 3, 4, 5, 6, 7, 8, 9};
  showvec(line);
  return 0;
}

Method a: for loop iteration output

void showvec(const vector<int>& line) {
  for (vector<int>::const_iterator iter = line.cbegin();iter != line.cend(); iter++) {
    cout << (*iter) << endl;
  }
}

Or c ++ using the new semantic auto

void showvec(const vector<int>& line) {
  for (auto iter = line.cbegin(); iter != line.cend(); iter++) {
    cout << (*iter) << endl;
  }
}

Method two: for_each plus function

template <typename T>
void printer(const T& line) {
  cout << line;
  cout << endl;
}

void showvec(const vector<int>& line) {
  for_each(line.cbegin(), line.cend(), printer<int>);
}

Method three: for traversing range

for (auto lin : line) {
    cout << lin;
  }