title: How to make negative of a variable? C++
body: <p>I apologize if this error is the result of a typo, but I can't figure out how to make my variable negative when the correct syntax should be y=-x;</p>
  
  <pre><code>std::cout &lt;&lt; "loop size = " &lt;&lt; loop_size_ &lt;&lt; std::endl;
  core::Size neg_loop_size_ = -loop_size_;
  std::cout &lt;&lt; "neg loop size = " &lt;&lt; neg_loop_size_ &lt;&lt; std::endl;
  </code></pre>
  
  <p>When I run it, this is the result I get:</p>
  
  <pre><code>loop size = 4
  neg loop size = 18446744073709551612
  </code></pre>
  
  <p>How do I get a new variable equal to -4?</p>