title: How to use conversion specifier character in C++?
body: <p>In Python I can do this:</p>
  
  <pre><code>print("Hello, %s!" % username)
  </code></pre>
  
  <p>How do I in C++ do the similar thing? I can do this, but it's probably not a good practice:</p>
  
  <pre><code>void welcome_message(std::string username) {
      std::cout &lt;&lt; "Hello, " &lt;&lt; username &lt;&lt; "!" &lt;&lt;std::endl;
  }
  </code></pre>