IIRC, importing an entire namespace into scope is a feature that was added exclusively for backwards compatibility and is not idiomatic modern C++.<p>What <i>is</i> idiomatic is explicitly importing individual symbols into a name peace.<p><pre><code>    #include &lt;iostream&gt;
    #include &lt;vector&gt;
    #include &lt;string&gt;
    
    using std::cout;
    using std::vector;
    using std::string;

    int main() { 
    
      vector&lt;string&gt; v {&quot;explicit &quot;, &quot;is better &quot;, &quot;than implicit\n&quot; };

      for (auto p: v) cout &lt;&lt; p;
      
      return 0;
      
    }
</code></pre>
I&#x27;m on mobile so please forgive errors.