What is the std::reverse() function in C++?

#include <vector>
#include <iostream>
// The following header needs to be included to use std::reverse()
#include <algorithm>
using namespace std;
int main() {
  std::vector<int> values = {
    1, 2, 3, 4, 5, 6, 7, 8, 9, 10
  };
  std::cout << "Before reversing: ";
  for(int x: values) {
    std::cout << x << ' ';
  }
  std::reverse(values.begin(), values.end());
  
  std::cout << "\nAfter reversing: ";
  for(int x: values) {
    std::cout << x << ' ';
  }
}

#include <string>
#include <iostream>
// The following header needs to be included to use std::reverse()
#include <algorithm>
using namespace std;
int main() {
  std::string sentence = "Hello, World!";
  std::cout << "Before reversing: " << sentence << '\n';
  std::reverse(sentence.begin(), sentence.end());
  std::cout << "After reversing: " << sentence << '\n';
}

#include <iostream>
// The following header needs to be included to use std::reverse()
#include <algorithm>
// The following header needs to be included to use std::begin() and std::end()
#include <iterator>
using namespace std;
int main() {
  int arr[] = {
    1, 2, 3, 4, 5, 6, 7, 8, 9, 10
  };
  std::cout << "Before reversing: ";
  for(int x: arr) {
    std::cout << x << ' ';
  }
  // built-in array has no begin() and end() member functions
  // but we can pass it to std::begin() and std::end()
  // in order to get the iterators we need
  std::reverse(std::begin(arr), std::end(arr));
  
  std::cout << "\nAfter reversing: ";
  for(int x: arr) {
    std::cout << x << ' ';
  }
}