align="left">data.frame</td>
<td align="left"><code>data.frame(a = 1)</code></td>
<td align="left">df[,1]</td>
</tr>
<tr class="even">
<td align="left"></td>
<td align="left">tbl_df</td>
<td align="left"><code>tibble(a = 1)</code></td>
<td align="left">tibble[,1]</td>
</tr>
<tr class="odd">
<td align="left">Unchanged</td>
<td align="left">AsIs</td>
<td align="left"><code>I(1L)</code></td>
<td align="left">I<int></td>
</tr>
<tr class="even">
<td align="left">vctrs types</td>
<td align="left">unspecified</td>