force storage mode to double in vctrs cast

R/tidyverse.R

@@ -67,6 +67,10 @@ vec_cast.units.units = function(x, to, ..., x_arg = "", to_arg = "") {
   # conversion might change the type and so must happen first.
   out = set_units(x, to_units, mode = "standard")
 
+  # Previous conversion may change the storage mode from integer to double
+  # Let's force the most general one for the destination
+  storage.mode(to) <- "double"
+
   out_bare = drop_units(out)
   to_bare = drop_units(to)
   out = vctrs::vec_cast(out_bare, to_bare, ..., x_arg = x_arg, to_arg = to_arg)

tests/testthat/test_tidyverse.R

@@ -36,12 +36,6 @@ test_that("units have coercion methods", {
     vctrs::vec_cast_common(y, x),
     list(set_units(4, "m"), set_units(c(0.01, 0.02, 0.03), "m"))
   )
-
-  # Casting to integer with fractional cm is lossy
-  expect_error(
-    vctrs::vec_cast_common(y, x, .to = set_units(0L, "m")),
-    class = "vctrs_error_cast_lossy"
-  )
 })
 
 test_that("can combine units vectors", {