title: Is a class with deleted copy-constructor trivially copyable?
body: <p>Is this class:</p>
  
  <pre><code>class A {
    public:
      A() = default;
      A(const A&amp;) = delete;
  };
  </code></pre>
  
  <p>trivially copyable? (At least clang seems to think so (<a href="http://coliru.stacked-crooked.com/a/3bf899de8625279d" rel="noreferrer">live</a>)) </p>
  
  <p>In particular, would</p>
  
  <pre><code>A a,b;
  std::memcpy(&amp;a, &amp;b, sizeof(A));
  </code></pre>
  
  <p>invoke undefined behavior?</p>
  
  <p>Context: <a href="https://stackoverflow.com/a/29759170/3002139">This answer</a> [deleted because proven wrong] plus its comment tree.</p>