Why does as_tibble() round floats to the nearest integer?

Question

When using as_tibble in dplyr 0.7.4 and R 3.4.1 I get the following outputs

mtcars %>% aggregate(disp ~ cyl, data=., mean) %>% as_tibble()

Answer 1

This is not a rounding, it's only a way for {tibble} to display data in a pretty way:

> mtcars %>% 
+   aggregate(disp ~ cyl, data=., mean) %>% 
+   as_tibble() %>% 
+   pull(disp)
[1] 105.1364 183.3143 353.1000

If you want to see more digits, you have to print a data.frame:

> mtcars %>% 
+   aggregate(disp ~ cyl, data=., mean) %>% 
+   as_tibble() %>% 
+   as.data.frame()
  cyl     disp
1   4 105.1364
2   6 183.3143
3   8 353.1000

(and yes, the two last lines are useless)