title: How to reorder data.table columns (without copying)
body: <p>I'd like to reorder columns in my <code>data.table</code> <code>x</code>, given a character vector of column names, <code>neworder</code>:</p>
  
  <pre><code>library(data.table)
  x &lt;- data.table(a = 1:3, b = 3:1, c = runif(3))
  neworder &lt;- c("c", "b", "a")
  </code></pre>
  
  <p>Obviously I could do:</p>
  
  <pre><code>x[ , neworder, with = FALSE]
  # or
  x[ , ..neworder]
  #            c b a
  # 1: 0.8476623 3 1
  # 2: 0.4787768 2 2
  # 3: 0.3570803 1 3
  </code></pre>
  
  <p>but that would require copying the entire dataset again. Is there another way to do this?</p>