lib/shift.cpp

The following code example is taken from the book
C++20 - The Complete Guide by Nicolai M. Josuttis, Leanpub, 2021
The code is licensed under a Creative Commons Attribution 4.0 International License.

---

// raw code

#include <iostream>
#include <vector>
#include <algorithm>
#include <ranges>

void print (const auto& coll)
{
  for (const auto& elem : coll) {
    std::cout << elem << ' ';
  }
  std::cout << '\n';
}

int main()
{
  std::vector coll{1, 2, 3, 4, 5, 6, 7, 8};

  print(coll);

  // shift one element to the front (returns new end):
  std::shift_left(coll.begin(), coll.end(), 1);
  print(coll);

  // shift three elements to the back (returns new begin):
  auto newbeg = std::shift_right(coll.begin(), coll.end(), 3);
  print(coll);
  print(std::ranges::subrange{newbeg, coll.end()});
}