title: "const std::stop_token&" or just "std::stop_token" as parameter for thread function?
body: <p>Since clang-tidy was complaining about &quot;The parameter 'stop_token' is copied for each invocation but only used as a const reference; consider making it a const reference&quot; I was asking myself the question, why every example I find about std::jthread/stop_token takes the stop_token by value, but I did not find any explanation for it.</p>
  <p>So, why take the stop_token by value?</p>
  <pre><code>1) void f(std::stop_token){};
  2) void f(const std::stop_token&amp;){};
  </code></pre>
  <p>Does it really matter when you can assume that the stop_token is the one generated by std::jthread?</p>
  <p>edit: This is asked purely out of curiosity and to not ignore a clang-tidy warning &quot;just because&quot;.</p>