title: Is it possible to modify a data.frame in-place (destructively)?
body: <p>It appears that one can add/delete a column to a <a href="https://cran.r-project.org/web/packages/data.table/" rel="nofollow noreferrer"><code>data.table</code></a> <em>in-place</em>, i.e., <strong>without copying</strong> all the other columns over to a new table.</p>
  
  <p>Is it possible to do that with a vanilla <a href="https://stat.ethz.ch/R-manual/R-devel/library/base/html/data.frame.html" rel="nofollow noreferrer"><code>data.frame</code></a>?</p>
  
  <p>PS. I know how to add/delete columns "functionally", i.e., creating a new frame without modifying the original one.</p>