title: How to combine views::enumerate and views::filter?
body: <p>I have a container that I want to filter.<br />
  I also need the index of the items later.<br />
  For that I want to use something like this:</p>
  <pre class="lang-cpp prettyprint-override"><code>auto items_to_remove = items | ranges::view::enumerate | ranges::view::filter(/*???*/);
  </code></pre>
  <p>What type do I have to use for the filter function?</p>
  <p>Edit: Here is my code/ error message:</p>
  <pre class="lang-cpp prettyprint-override"><code>auto f = [](const auto&amp; pair) {
              return true;
          };
  auto items_to_remove = level.items | ranges::views::enumerate | ranges::views::filter(f);
  </code></pre>
  <p><a href="https://i.stack.imgur.com/Weppq.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Weppq.png" alt="enter image description here" /></a></p>