[libc++][ranges] Finish LWG issues directly related to the One Ranges Proposal.
- P1252 ("Ranges Design Cleanup") -- deprecate
`move_iterator::operator->` starting from C++20; add range comparisons
to the `<functional>` synopsis. This restores
`move_iterator::operator->` that was incorrectly deleted in D117656;
it's still defined in the latest draft, see
http://eel.is/c++draft/depr.move.iter.elem. Note that changes to
`*_result` types from 6.1 in the paper are no longer relevant now that
these types are aliases;
- P2106 ("Alternative wording for GB315 and GB316") -- add a few
`*_result` types to the synopsis in `<algorithm>` (some algorithms are
not implemented yet and thus some of the proposal still cannot be
marked as done);
Also mark already done issues as done (or as nothing to do):
- P2091 ("Fixing Issues With Range Access CPOs") was already implemented
(this patch adds tests for some ill-formed cases);
- LWG 3247 ("`ranges::iter_move` should perform ADL-only lookup of
`iter_move`") was already implemented;
- LWG 3300 ("Non-array ssize overload is underconstrained") doesn't
affect the implementation;
- LWG 3335 ("Resolve C++20 NB comments US 273 and GB 274") was already
implemented;
- LWG 3355 ("The memory algorithms should support move-only input
iterators introduced by P1207") was already implemented (except for
testing).
Differential Revision: https://reviews.llvm.org/D126053
diff --git a/libcxx/include/algorithm b/libcxx/include/algorithm
index 9ae6471..62b67c3 100644
--- a/libcxx/include/algorithm
+++ b/libcxx/include/algorithm
@@ -19,12 +19,17 @@
{
namespace ranges {
+
+ // [algorithms.results], algorithm result types
template <class I, class F>
struct in_fun_result; // since C++20
template <class I1, class I2>
struct in_in_result; // since C++20
+ template <class I, class O>
+ struct in_out_result; // since C++20
+
template <class I1, class I2, class O>
struct in_in_out_result; // since C++20
@@ -53,6 +58,9 @@
indirect_strict_weak_order<projected<iterator_t<R>, Proj>> Comp = ranges::less>
constexpr borrowed_iterator_t<R> ranges::max_element(R&& r, Comp comp = {}, Proj proj = {}); // since C++20
+ template<class I1, class I2>
+ using mismatch_result = in_in_result<I1, I2>;
+
template <input_iterator I1, sentinel_for<_I1> S1, input_iterator I2, sentinel_for<_I2> S2,
class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
requires indirectly_comparable<I1, I2, Pred, Proj1, Proj2>
@@ -174,6 +182,9 @@
constexpr range_difference_t<R>
count_if(R&& r, Pred pred, Proj proj = {}); // since C++20
+ template<class T>
+ using minmax_result = min_max_result<T>;
+
template<class T, class Proj = identity,
indirect_strict_weak_order<projected<const T*, Proj>> Comp = ranges::less>
constexpr ranges::minmax_result<const T&>
@@ -190,6 +201,9 @@
constexpr ranges::minmax_result<range_value_t<R>>
minmax(R&& r, Comp comp = {}, Proj proj = {}); // since C++20
+ template<class I>
+ using minmax_element_result = min_max_result<I>;
+
template<forward_iterator I, sentinel_for<I> S, class Proj = identity,
indirect_strict_weak_order<projected<I, Proj>> Comp = ranges::less>
constexpr ranges::minmax_element_result<I>
@@ -201,10 +215,10 @@
minmax_element(R&& r, Comp comp = {}, Proj proj = {}); // since C++20
template<class I, class O>
- using copy_result = in_out_result<I, O>; // since C++20
+ using copy_result = in_out_result<I, O>; // since C++20
- template<class I, class O>
- using copy_n_result = in_out_result<I, O>; // since C++20
+ template<class I, class O>
+ using copy_n_result = in_out_result<I, O>; // since C++20
template<class I, class O>
using copy_if_result = in_out_result<I, O>; // since C++20
@@ -638,19 +652,34 @@
copy_backward(BidirectionalIterator1 first, BidirectionalIterator1 last,
BidirectionalIterator2 result);
+// [alg.move], move
+template<class InputIterator, class OutputIterator>
+ constexpr OutputIterator move(InputIterator first, InputIterator last,
+ OutputIterator result);
+
+template<class BidirectionalIterator1, class BidirectionalIterator2>
+ constexpr BidirectionalIterator2
+ move_backward(BidirectionalIterator1 first, BidirectionalIterator1 last,
+ BidirectionalIterator2 result);
+
template <class ForwardIterator1, class ForwardIterator2>
constexpr ForwardIterator2 // constexpr in C++20
swap_ranges(ForwardIterator1 first1, ForwardIterator1 last1, ForwardIterator2 first2);
+namespace ranges {
+ template<class I1, class I2>
+ using swap_ranges_result = in_in_result<I1, I2>;
+
template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2>
requires indirectly_swappable<I1, I2>
constexpr ranges::swap_ranges_result<I1, I2>
- ranges::swap_ranges(I1 first1, S1 last1, I2 first2, S2 last2);
+ swap_ranges(I1 first1, S1 last1, I2 first2, S2 last2);
template<input_range R1, input_range R2>
requires indirectly_swappable<iterator_t<R1>, iterator_t<R2>>
constexpr ranges::swap_ranges_result<borrowed_iterator_t<R1>, borrowed_iterator_t<R2>>
- ranges::swap_ranges(R1&& r1, R2&& r2);
+ swap_ranges(R1&& r1, R2&& r2);
+}
template <class ForwardIterator1, class ForwardIterator2>
constexpr void // constexpr in C++20
