title: assert in foreach causes too few argument lists for macro invocation
body: <p>I'm using scala test to check if <code>Array</code> contains <code>Array</code>s of given size:</p>
  
  <pre><code>result.map(_.length == 2).foreach(assert)
  </code></pre>
  
  <p>This causes compilation error:</p>
  
  <pre><code>Error:(34, 39) too few argument lists for macro invocation
      result.map(_.length == 2).foreach(assert)
  </code></pre>
  
  <p>although intellij does not indicate compilation error. How to test it?</p>