title: excluding FALSE elements from a character vector by using logical vector
body: <p>I manage to do the following: </p>
  
  <pre><code>stuff &lt;- c("banana_fruit","apple_fruit","coin","key","crap")
  fruits &lt;- stuff[stuff %in% grep("fruit",stuff,value=TRUE)]
  </code></pre>
  
  <p>but I can't get select the-not-so-healthy stuff with the usual thoughts and ideas like</p>
  
  <pre><code>no_fruit &lt;- stuff[stuff  %not in% grep("fruit",stuff,value=TRUE)]
  #or
  no_fruit &lt;- stuff[-c(stuff  %in% grep("fruit",stuff,value=TRUE))]
  </code></pre>
  
  <p>don't work. The latter just ignores the "-"</p>