invoke_map not working with dates

[jeremystan]

invoke_map does not work with a list of dates:

library(purrr)
day <- as.Date("2016-09-01")
num <- 1
invoke_map(list(identity), list(num))
#> [[1]]
#> [1] 1
#> 
invoke_map(list(identity), list(day))
#> Error in do.call(.f, c(.x, list(...)), envir = .env) :
#>   second argument must be a list

> sessionInfo()
R version 3.3.1 (2016-06-21)
Platform: x86_64-apple-darwin13.4.0 (64-bit)
Running under: OS X 10.11.6 (El Capitan)

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base

other attached packages:
[1] purrr_0.2.2

loaded via a namespace (and not attached):
[1] lazyeval_0.2.0 magrittr_1.5   Rcpp_0.12.6