The following code example is taken from the book
C++17 - The Complete Guide by Nicolai M. Josuttis, Leanpub, 2017
The code is licensed under a Creative Commons Attribution 4.0 International License. Creative Commons License

// raw code

#include "pmrcustomer.hpp"
#include "tracker.hpp"
#include <vector>

int main()
  Tracker tracker;
  std::pmr::vector<PmrCustomer> coll(&tracker);
  coll.reserve(100);                     // allocates with tracker

  PmrCustomer c1{"Peter, Paul & Mary"};  // allocates with get_default_resource()
  coll.push_back(c1);                    // allocates with vector allocator (tracker)
  coll.push_back(std::move(c1));         // copies (allocators not interchangeable)

  for (const auto& cust : coll) {
    std::cout << cust.getName() << '\n';