title: An option to not suppress output after := assignment in data.table
body: <p>This is related to <a href="https://stackoverflow.com/questions/32988099/data-table-objects-not-printed-after-returned-from-function">data.table objects not printed after returned from function</a> but is not a dupe. This question is to specifically look for a way to not suppress output when using an assignment <code>:=</code> data.table line at the repl. So in cases where an eval would cause R to call the print method.</p>
  
  <p>I've upgraded and noticed that <code>:=</code> returns invisibly now. As I develop with an interactive workflow this disrupts the flow when I am building a pipeline, add an assignment <code>:=</code> line, and then expect to see the results to use as context for adding an additional step. </p>
  
  <p>Sure I can add <code>[]</code> to the assignment lines, but this would be after realizing that my assignment line didn't print (because I didn't do this prior), and so my flow was just disrupted prior to adding this. Or, one might argue that I should always tack on <code>[]</code> with every assignment line so that my flow isn't disrupted, but then I have to remember to do that for only assignment lines, and since a pipeline commonly mixes assignment with filter, in practice this introduces extra cognitive overhead that - to an end user - feels unnecessary and looks inconsistent when going line by line in the pipeline.</p>
  
  <p>I would rather not argue about choosing to return invisibly or not, as I figure this has been thoroughly discussed already, and the correct decision for the majority of people and use cases has been made. Instead, is there an option I can set or workaround to have <code>:=</code> not return invisibly?</p>