lib/foreachmove.cpp

The following code example is taken from the book
C++ Move Semantics - The Complete Guide by Nicolai M. Josuttis, Leanpub, 2020
The code is licensed under a Creative Commons Attribution 4.0 International License.

---

// raw code

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>

template<typename T>
void print(const std::string& name, const T& coll)
{
  std::cout << name << " (" << coll.size() << " elems): ";
  for (const auto& elem : coll) {
    std::cout << " \"" << elem << "\"";
  }
  std::cout << "\n";
}

void process(std::string s)  // gets moved value from rvalues
{
  std::cout << "- process(" << s << ")\n";
  //...
}                

int main()
{
  std::vector<std::string> coll{"don't", "vote", "for", "liars"};
  print("coll", coll);
  
  // move away only the elements processed:
  std::for_each(std::make_move_iterator(coll.begin()),
                std::make_move_iterator(coll.end()),
                [] (auto&& elem) {
                  if (elem.size() != 4) {
                    process(std::move(elem));
                  }
                });

  print("coll", coll);
}