vctrs 0.5.0

• vctrs is now compliant with -Wstrict-prototypes as requested by CRAN
  (#1729).

• vec_ptype2() now consistently falls back to bare data frame in
  case of incompatible data frame subclasses. This is part of a
  general move towards relaxed coercion rules.

• Common type and cast errors now inherit from "vctrs_error_ptype2"
  and "vctrs_error_cast" respectively. They are still both
  subclasses from "vctrs_error_incompatible_type" (which used to be
  their most specific class and is now a parent class).

• New list_all_size() and list_check_all_size() to quickly determine if a
  list contains elements of a particular size (#1582).

• list_unchop() has gained empty ... to force optional arguments to be
  named (#1715).

• vec_rep_each(times = 0) now works correctly with logical vectors that are
  considered unspecified and with named vectors (#1673).

• list_of() was relaxed to make it easier to combine. It is now
  coercible with list() (#1161). When incompatible list_of() types
  are combined, the result is now a bare list().

  Following this change, the role of list_of() is mainly to carry
  type information for potential optimisations, rather than to
  guarantee a certain type throughout an analysis.

• validate_list_of() has been removed. It hasn't proven to be practically
  useful, and isn't used by any packages on CRAN (#1697).

• Directed calls to vec_c(), like vec_c(.ptype = <type>), now mention the
  position of the problematic argument when there are cast errors (#1690).

• list_unchop() no longer drops names in some cases when indices were
  supplied (#1689).

• "unique_quiet" and "universal_quiet" are newly accepted by
  vec_as_names(repair =) and vec_names2(repair =). These options exist to
  help users who call these functions indirectly, via another function which
  only exposes repair but not quiet. Specifying repair = "unique_quiet" is
  like specifying repair = "unique", quiet = TRUE. When the "*_quiet"
  options are used, any setting of quiet is silently overridden (@jennybc,
  #1629).

  "unique_quiet" and "universal_quiet" are also newly accepted for the name
  repair argument of several other functions that do not expose a quiet
  argument: data_frame(), df_list(), vec_c(), list_unchop(),
  vec_interleave(), vec_rbind(), and vec_cbind() (@jennybc, #1716).

• list_unchop() has gained error_call and error_arg arguments (#1641,
  #1692).

• vec_c() has gained .error_call and .error_arg arguments (#1641, #1692).

• Improved the performance of list-of common type methods (#1686, #875).

• The list-of method for as_list_of() now places the optional .ptype
  argument after the ... (#1686).

• vec_rbind() now applies base::c() fallback recursively within
  packed df-cols (#1331, #1462, #1640).

• vec_c(), vec_unchop(), and vec_rbind() now proxy and restore
  recursively (#1107). This prevents vec_restore() from being called
  with partially filled vectors and improves performance (#1217,
  #1496).

• New vec_any_missing() for quickly determining if a vector has any missing
  values (#1672).

• vec_equal_na() has been renamed to vec_detect_missing() to align better
  with vctrs naming conventions. vec_equal_na() will stick around for a few
  minor versions, but has been formally soft-deprecated (#1672).

• vec_c(outer = c(inner = 1)) now produces correct error messages (#522).

• If a data frame is returned as the proxy from vec_proxy_equal(),
  vec_proxy_compare(), or vec_proxy_order(), then the corresponding proxy
  function is now automatically applied recursively along all of the columns.
  Additionally, packed data frame columns will be unpacked, and 1 column data
  frames will be unwrapped. This ensures that the simplest possible types are
  provided to the native C algorithms, improving both correctness and
  performance (#1664).

• When used with record vectors, vec_proxy_compare() and vec_proxy_order()
  now call the correct proxy function while recursing over the fields (#1664).

• The experimental function vec_list_cast() has been removed from
  the package (#1382).

• Native classes like dates and datetimes now accept dimensions (#1290, #1329).

• vec_compare() now throws a more informative error when attempting to compare
  complex vectors (#1655).

• vec_rep() and friends gain error_call, x_arg, and times_arg
  arguments so they can be embedded in frontends (#1303).

• Record vectors now fail as expected when indexed along dimensions
  greater than 1 (#1295).

• vec_order() and vec_sort() now have ... between the required and
  optional arguments to make them easier to extend (#1647).

• S3 vignette was extended to show how to make the polynomial class
  atomic instead of a list (#1030).

• The experimental n argument of vec_restore() has been
  removed. It was only used to inform on the size of data frames in
  case a bare list is restored. It is now expected that bare lists be
  initialised to data frame so that the size is carried through row
  attributes. This makes the generic simpler and fixes some
  performance issues (#650).

• The anyNA() method for vctrs_vctr (and thus vctrs_list_of) now
  supports the recursive argument (#1278).

• vec_as_location() and num_as_location() have gained a missing = "remove"
  option (#1595).

• vec_as_location() no longer matches NA_character_ and "" indices if
  those invalid names appear in names (#1489).

• vec_unchop() has been renamed to list_unchop() to better indicate that it
  requires list input. vec_unchop() will stick around for a few minor
  versions, but has been formally soft-deprecated (#1209).

• Lossy cast errors during scalar subscript validation now have the
  correct message (#1606).

• Fixed confusing error message with logical [[ subscripts (#1608).

• New vec_rank() to compute various types of sample ranks (#1600).

• num_as_location() now throws the right error when there are out-of-bounds
  negative values and oob = "extend" and negative = "ignore" are set
  (#1614, #1630).

• num_as_location() now works correctly when a combination of zero = "error"
  and negative = "invert" are used (#1612).

• data_frame() and df_list() have gained .error_call arguments (#1610).

• vec_locate_matches() has gained an error_call argument (#1611).

• "select" and "relocate" have been added as valid subscript actions to
  support tidyselect and dplyr (#1596).

• num_as_location() has a new oob = "remove" argument to remove
  out-of-bounds locations (#1595).

• vec_rbind() and vec_cbind() now have .error_call arguments (#1597).

• df_list() has gained a new .unpack argument to optionally disable data
  frame unpacking (#1616).

• vec_check_list(arg = "") now throws the correct error (#1604).

• The difftime to difftime vec_cast() method now standardizes the internal
  storage type to double, catching potentially corrupt integer storage
  difftime vectors (#1602).

• vec_as_location2() and vec_as_subscript2() more correctly utilize their
  call arguments (#1605).

• vec_count(sort = "count") now uses a stable sorting method. This ensures
  that different keys with the same count are sorted in the order that they
  originally appeared in (#1588).

• Lossy cast error conditions now show the correct message when
  conditionMessage() is called on them (#1592).

• Fixed inconsistent reporting of conflicting inputs in
  vec_ptype_common() (#1570).

• vec_ptype_abbr() and vec_ptype_full() now suffix 1d arrays
  with [1d].

• vec_ptype_abbr() and vec_ptype_full() methods are no longer
  inherited (#1549).

• vec_cast() now throws the correct error when attempting to cast a subclassed
  data frame to a non-data frame type (#1568).

• vec_locate_matches() now uses a more conservative heuristic when taking the
  joint ordering proxy. This allows it to work correctly with sf's sfc vectors
  and the classes from the bignum package (#1558).

• An sfc method for vec_proxy_order() was added to better support the sf
  package. These vectors are generally treated like list-columns even though
  they don't explicitly have a "list" class, and the vec_proxy_order()
  method now forwards to the list method to reflect that (#1558).

• vec_proxy_compare() now works correctly for raw vectors wrapped in I().
  vec_proxy_order() now works correctly for raw and list vectors wrapped in
  I() (#1557).