walk2 unclasses dates but other functions don't

[gergness]

I find this behavior confusing - walk2 is the only function out of map, map2, walk and walk2 that loses the class on dates. I believe it is due to the transpose in pwalk (and so is related to #471), but because map2 doesn't have this behavior I thought there may be another way to solve this.

library(purrr)
dates <- seq(as.Date('2018-07-01'), as.Date('2018-07-02'), by = "day")

walk2(dates, dates, ~print(.x))
#> [1] 17713
#> [1] 17714

map(dates, ~.)
#> [[1]]
#> [1] "2018-07-01"
#> 
#> [[2]]
#> [1] "2018-07-02"
map2(dates, dates, ~.x)
#> [[1]]
#> [1] "2018-07-01"
#> 
#> [[2]]
#> [1] "2018-07-02"
walk(dates, ~print(.))
#> [1] "2018-07-01"
#> [1] "2018-07-02"

Created on 2018-07-10 by the reprex package (v0.2.0).

[lionel-]

This was fixed in #554 thanks to @mikmart :)