title: What is the impact of Importing modules using barrels vs specific files on the bundle size?
body: <p>According to angular 2 style guide, it is a good practice to define a file for each directory that will contain all the imports of the nested files.</p>
  
  <p>I completely agree with that and have already started using this approach.</p>
  
  <p>Now, my questions is: </p>
  
  <p>Is there any impact on the final bundle size depending on each approach I use?</p>
  
  <p>For instance this(Considering that /core has dozens of exportable classes:</p>
  
  <pre><code>import {DataClient} from './../core'
  </code></pre>
  
  <p>vs this:</p>
  
  <pre><code>import {DataClient} from './../core/interfaces/data.service'
  </code></pre>
  
  <p>Additionally, what happens for third party libs, like rxjs? Whats the difference between the following snippets?</p>
  
  <pre><code>import {Observable} from 'rxjs'
  
  import {Observable} from 'rxjs/Observable'
  </code></pre>
  
  <p>I mentioned rxjs because even in angular documentation is advised to import each operator separately. </p>