title: How to define a JSON array with concrete item definition for every index (i.e. a tuple) in OpenAPI?
body: <p>I need to define in OpenAPI a JSON response with an array. The array always contains 2 items and the first one is always a number and second one is always a string.</p>
  
  <pre><code>[1, "a"]    //valid
  ["a", 1]    //invalid
  [1]         //invalid
  [1, "a", 2] //invalid
  </code></pre>
  
  <p>I've found out that JSON schema does support that by passing a list of items in <code>items</code> instead of single object (<a href="https://json-schema.org/understanding-json-schema/reference/array.html" rel="nofollow noreferrer">source</a>), but OpenAPI explicitly forbids that and accepts only a single object (<a href="http://spec.openapis.org/oas/v3.0.2#schema-object" rel="nofollow noreferrer">source</a>). How can that be expressed in OpenAPI?</p>