title: How to use parameter to initialize the size of std::array in a class constructor?
body: <p>For example:</p>
  
  <pre><code>#Include &lt;array&gt;
  
  class UnionFind final {
   public:
    explicit UnionFind(int numbers) {
      // ???
    }
  
   private:
    std::array&lt;int, ???&gt; array_;
  };
  </code></pre>
  
  <p>I want to initialize <code>array_</code> as <code>std::array&lt;int, numbers&gt;</code> in the constructor <code>UnionFind(int numbers)</code>, but I do not know how to do it.</p>