title: How is the way to insert dynamically one pair to may unordered_list?
body: <p>If I have one <code>unordered_map</code> and I want insert in a for dynamically the value iterated, but always the <code>std::unordered_map::insert</code> insert only once.</p>
  
  <pre><code>unordered_map&lt;string, string&gt; legalities;
  vector&lt;string&gt; values = {"foo", "bar"};
  
  for(auto&amp; value : values) {
    legalities.insert({ "foo", value });
    cout &lt;&lt; value &lt;&lt; endl;
  }
  
  legalities.size(); // return 1
  </code></pre>
  
  <p>How I can insert in this way?</p>