title: Returning a logical vector for matches: regexp supported?
body: <p>I want to return a logical vector for regexp matches over a character vector, but match or %in do not seem to support regular expressions, e.g.:</p>
  
  <pre><code>&gt; x &lt;- c("Bill", "Brett", "Jane")
  &gt; grep("^B", x)
  [1] 1 2
  &gt; x %in% "^B"
  [1] FALSE FALSE FALSE
  </code></pre>
  
  <p>I would like this to return </p>
  
  <pre><code>[1] TRUE TRUE FALSE
  </code></pre>
  
  <p>Ideas?</p>
  
  <p>Thanks,</p>
  
  <p>Roberto</p>