title: Is a contiguous_range always a sized_range?
body: <p>I have the following question concerning the ranges library in C++20:</p>
  <p>Let <code>std::ranges::contiguous_range&lt;T&gt;</code> for an <em>arbitrary</em> type T.</p>
  <p>Can I assume <code>std::ranges::sized_range&lt;T&gt;</code>?</p>