map_dtc doesnt work when the mapped call return dts

[berndbischl]

i would like to do this

foo = function(mu) {
  setDT(as.data.frame(rnorm(2, mean = mu)))
}
d = map_dtc(1:3, foo) # doenst work
print(d)

# this works
d = lapply(1:3, foo)
d = do.call(cbind, d)
print(d)