title: How to return a const value?
body: <p>I want to write a small factorial library. Please look at the code inside the main module of the library:</p>
  
  <pre><code>pub fn results() -&gt; const [i8; 6] { [
        1,
        1,
        2,
        6,
       24,
      120,
      //720 is too large for i8.
  ] }
  
  pub fn results() -&gt; const [i32; 13] { [
                1,
                1,
                2,
                6,
               24,
              120,
              720,
            5_040,
           40_320,
          362_880,
        3_628_800,
       39_916_800,
      479_001_600,
      //6_227_020_800 is too large for i32.
  ] }
  </code></pre>
  
  <p>It gives me this error for the return type of the first function:</p>
  
  <pre class="lang-none prettyprint-override"><code>error: expected type, found keyword `const`
   --&gt; src/main.rs:1:21
    |
  1 | pub fn results() -&gt; const [i8; 6] { [
    |                     ^^^^^
  </code></pre>
  
  <p>The goal is to get an array of all possible factorial values at compile time.</p>