title: std::bind null function pointer
body: <pre><code>#include &lt;iostream&gt;
  #include &lt;functional&gt;
  
  typedef int(*SumFptr)(int,int);
  
  int main()
  {
  
      SumFptr ptr = nullptr;
      std::function&lt;int(int)&gt; func = std::bind(ptr, std::placeholders::_1, 42);
      std::cout &lt;&lt; (func ? "true" : "false") &lt;&lt; std::endl;
  
      return 0;
  }
  </code></pre>
  
  <p>The output is true. </p>
  
  <p>My expectation was false, like <code>std::function{nullptr}</code>. Is it a bug or correct behaviour and where can I read about it?</p>