// atomic::operator=/operator T example:
#include <iostream>       // std::cout
#include <atomic>         // std::atomic
#include <thread>         // std::thread, std::this_thread::yield
 
std::atomic<int> foo {0};
 
void set_foo(int x) {
  foo = x;
}
 
void print_foo() {
  while (foo==0) {             // wait while foo=0
    std::this_thread::yield();
  }
  std::cout << "foo: " << foo << '\n';
}
 
int main ()
{
  std::thread first (print_foo);
  std::thread second (set_foo,10);
  first.join();
  second.join();
  return 0;
}

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