anchor.diff:    - [Inside the *NgSwitch* directives](#ngSwitch)
     - [Prefer the (*) prefix](#prefer-asterisk)
     - [The &lt;template> element](#template)
  +  - [Group sibling elements with &lt;ng-container&gt;](#ng-container)
     - [Write a structural directive](#unless)
   
     Try the <live-example></live-example>.
  
positive.code:   Before applying a structural directive, you might want to pause for a moment 
    to consider the consequences of adding and removing elements and of creating and destroying components.
  
  a#ngcontainer
  a#ng-container
  .l-main-section
  
negative.code: 
    - [What are structural directives?](#definition)
    - [*NgIf* case study](#ngIf)
    - [The asterisk (*) prefix](#asterisk)
    - [Inside *NgFor*](#ngFor)
      - [microsyntax](#microsyntax)
  