title: Error in View() data.frame containing int64 in RStudio
body: <p>I've noticed a problem when attempting to <code>View()</code> data.frames/.tables with <code>int64</code> columns in RStudio (using v0.99.892, but problem is not version specific).</p>
  
  <pre><code>&gt; dt2
     a          b          c
  1: 1 -126208802   84258755
  2: 2 -126194884 1402875037
  3: 3 -126199178         NA
  4: 4 -126198991  778459540
  5: 5 -126200004   42143878
  
  &gt; dput(dt2)
  structure(list(a = 1:5, b = c(-126208802L, -126194884L, -126199178L, 
  -126198991L, -126200004L), c = structure(c(4.16293562068544e-316, 
  6.93112361189968e-315, 0, 3.8461011539138e-315, 2.08218423023247e-316
  ), class = "integer64")), .Names = c("a", "b", "c"), class = c("data.table", 
  "data.frame"), row.names = c(NA, -5L), .internal.selfref = &lt;pointer: 0x0000000000230788&gt;)
  
  &gt; View(dt2)
  Error in if (col_min &lt; col_max) { : missing value where TRUE/FALSE needed
  
  &gt; View(as.data.frame(dt2)) # maybe it's data.table? -- nope
  Error in if (col_min &lt; col_max) { : missing value where TRUE/FALSE needed
  
  &gt; View(dt2[,1:2, with=FALSE]) # works if you drop the int64 column 
  </code></pre>
  
  <p>The following question does not address these particular circumstances:  <a href="https://stackoverflow.com/questions/7355187/error-in-if-while-condition-missing-value-where-true-false-needed">Error in if/while (condition) {: missing Value where TRUE/FALSE needed</a></p>
  
  <p>My current workaround is just to drop the int64 columns:</p>
  
  <pre><code>View2 &lt;- function(dt){
    View(dt[, which(sapply(dt, class) != "integer64"), with=FALSE])
  }
  </code></pre>
  
  <p>But I work with big integers a lot (typically as keys) and it would be super helpful to be able to just View() the darn things.  Any advice?</p>
  
  <p>I'm running R 3.2.3 on Windows 7 x64.</p>