title: When should a Scala method def use an explicitly defined return type?
body: <p>Scala-style-guide suggest to always explicitly define return type expect when used <code>Unit</code>: </p>
  
  <blockquote>
    <p>Methods should be declared according to the following pattern:</p>
  
  <pre><code>def foo(bar: Baz): Bin = expr
  </code></pre>
    
    <p>The only exceptions to this rule are methods which return Unit. Such
    methods should use Scala's syntactic sugar to avoid accidentally
    confusing return types:</p>
  
  <pre><code>def foo(bar: Baz) { // return type is Unit
    expr
  }
  </code></pre>
  </blockquote>