title: Is deleting all rows in an R data frame using [-0,] officially supported?
body: <p>I have found that I can delete all rows of an R data frame by subsetting with the square bracket function and using -0 as the row index. However, I have not been able to find any documentation saying this is an official behavior that I can count on being there in the future. Is this an official function that I can use with confidence expecting that it will continue to function that way in future releases?</p>
  
  <pre><code>&gt; df &lt;- data.frame(c1=c(1,2,3),c2=c(2,3,4), c3=c(4,5,6))
  &gt; df
    c1 c2 c3
  1  1  2  4
  2  2  3  5
  3  3  4  6  
  &gt; df[-0,]
  [1] c1 c2 c3
  &lt;0 rows&gt; (or 0-length row.names)
  </code></pre>