title: Does std::atomic<struct> makes all member also atomic?
body: <p>Lets say we have  a structure as below-</p>
  
  <pre><code>struct test
  {
      int a;
      int b;
  };
  </code></pre>
  
  <p>I make a atomic variable of this structure and try to update a and b. Will these operations be atomic? What does it mean to make a structure/class atomic?</p>
  
  <pre><code>std::atomic&lt;test&gt; t;
  t.a = 10;   // is this an atomic operation?
  t.b = 20;   // is this an atomic operation?
  // I understand a and b are not atomic in themselves but I am confused     
  // as to when you say struct temp is atomic what does it mean?
  // does it mean the t instance's this pointer is atomic?
  </code></pre>