[libc++][ranges] Temporarily mark `ranges::join_view` as experimental.

[var-const]

Summary

This is in anticipation of https://isocpp.org/files/papers/D2770R0.html,
which is ABI-breaking for join_view.

[ldionne]

LGTM w/ changes and green CI

libcxx/include/__config

256 ↗

(On Diff #491975)

I would avoid introducing this macro and simply use _LIBCPP_ENABLE_EXPERIMENTAL directly from join_view.

libcxx/test/libcxx/experimental/fexperimental-library.compile.pass.cpp

32–35 ↗

(On Diff #491975)

This can go away.

libcxx/test/std/ranges/range.adaptors/range.join.view/adaptor.pass.cpp

10

I would simply use UNSUPPORTED: !c++experimental

[var-const]

Address feedback.

[var-const]

Address feedback and rebase

[var-const]

@ldionne Hmm, how do I reconcile the change to release notes with https://github.com/llvm/llvm-project/commit/603c286334b07f568d39f6706c848f576914f323 that bumped the version to 17 and removed the 16's notes?

[var-const]

Remove release notes from this patch.

libcxx/include/__ranges/join_view.h

 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if _LIBCPP_STD_VER > 17
+// Note: `join_view` is still marked experimental because there is an ABI-breaking change that affects `join_view` in
+// the pipeline (https://isocpp.org/files/papers/D2770R0.html).
+// TODO: make `join_view` non-experimental once D2770 is implemented.
+#if _LIBCPP_STD_VER > 17 && defined(_LIBCPP_ENABLE_EXPERIMENTAL)
 
 namespace ranges {
   template<class>
   struct __join_view_iterator_category {};
 
   template<class _View>
     requires is_reference_v<range_reference_t<_View>> &&
              forward_range<_View> &&
struct __segmented_iterator_traits<ranges::__join_view_iterator<_View, _Const>> {
 
   static constexpr _LIBCPP_HIDE_FROM_ABI _JoinViewIterator
   __compose(__segment_iterator __seg_iter, __local_iterator __local_iter) {
       return _JoinViewIterator(
           std::move(__seg_iter).__get_data(), std::move(__seg_iter).__get_iter(), std::move(__local_iter));
   }
 };
 
-#endif // _LIBCPP_STD_VER > 17
+#endif // #if _LIBCPP_STD_VER > 17 && defined(_LIBCPP_ENABLE_EXPERIMENTAL)
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP___RANGES_JOIN_VIEW_H

libcxx/test/std/algorithms/alg.modifying.operations/alg.copy/ranges.copy.segmented.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// TODO: make `join_view` non-experimental once D2770 is implemented.
+// UNSUPPORTED: !c++experimental
 
 #include <algorithm>
 #include <array>
 #include <cassert>
 #include <concepts>
 #include <deque>
 #include <ranges>
 #include <vector>

libcxx/test/std/algorithms/alg.modifying.operations/alg.copy/ranges.copy_backward.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <algorithm>
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
-
+// TODO: make `join_view` non-experimental once D2770 is implemented.
+// UNSUPPORTED: !c++experimental
 
 // template<bidirectional_iterator I1, sentinel_for<I1> S1, bidirectional_iterator I2>
 //   requires indirectly_copyable<I1, I2>
 //   constexpr ranges::copy_backward_result<I1, I2>
 //     ranges::copy_backward(I1 first, S1 last, I2 result);
 // template<bidirectional_range R, bidirectional_iterator I>
 //   requires indirectly_copyable<iterator_t<R>, I>
 //   constexpr ranges::copy_backward_result<borrowed_iterator_t<R>, I>

libcxx/test/std/library/description/conventions/customization.point.object/cpo.compile.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// TODO: make `join_view` non-experimental once D2770 is implemented.
+// UNSUPPORTED: !c++experimental
 
 // [customization.point.object]
 // [range.adaptor.object] "A range adaptor object is a customization point object..."
 
 #include <compare>
 #include <concepts>
 #include <iterator>
 #include <ranges>

libcxx/test/std/ranges/range.adaptors/range.join.view/adaptor.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 // std::views::join
 
 #include <ranges>
 
 #include <cassert>
 #include <type_traits>
 

libcxx/test/std/ranges/range.adaptors/range.join.view/base.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 // constexpr V base() const& requires copy_constructible<V>;
 // constexpr V base() &&;
 
 #include <cassert>
 #include <ranges>
 
 #include "test_macros.h"

libcxx/test/std/ranges/range.adaptors/range.join.view/begin.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 // constexpr auto begin();
 // constexpr auto begin() const
 //    requires input_range<const V> &&
 //             is_reference_v<range_reference_t<const V>>;
 
 #include <cassert>
 #include <ranges>

libcxx/test/std/ranges/range.adaptors/range.join.view/ctad.compile.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 // template<class R>
 //   explicit join_view(R&&) -> join_view<views::all_t<R>>;
 
 #include <ranges>
 #include <utility>
 
 struct Child {

libcxx/test/std/ranges/range.adaptors/range.join.view/ctad.verify.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 // template<class R>
 //   explicit join_view(R&&) -> join_view<views::all_t<R>>;
 
 // Tests that the deduction guide is explicit.
 
 #include <ranges>
 

libcxx/test/std/ranges/range.adaptors/range.join.view/ctor.default.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 // join_view() requires default_initializable<V> = default;
 
 #include <cassert>
 #include <ranges>
 
 #include "types.h"
 

libcxx/test/std/ranges/range.adaptors/range.join.view/ctor.view.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 // constexpr explicit join_view(V base);
 
 #include <cassert>
 #include <ranges>
 
 #include "test_macros.h"
 #include "types.h"

libcxx/test/std/ranges/range.adaptors/range.join.view/end.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 // constexpr auto end();
 // constexpr auto end() const;
 
 #include <cassert>
 #include <ranges>
 #include <type_traits>
 

libcxx/test/std/ranges/range.adaptors/range.join.view/general.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 // General tests for join_view. This file does not test anything specifically.
 
 #include <algorithm>
 #include <cassert>
 #include <ranges>
 #include <string>
 #include <vector>

libcxx/test/std/ranges/range.adaptors/range.join.view/iterator/arrow.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 // constexpr InnerIter operator->() const
 //   requires has-arrow<InnerIter> && copyable<InnerIter>;
 
 #include <cassert>
 #include <ranges>
 
 #include "../types.h"

libcxx/test/std/ranges/range.adaptors/range.join.view/iterator/ctor.default.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 // iterator() requires default_initializable<OuterIter> = default;
 
 #include <ranges>
 
 #include <cassert>
 #include <type_traits>
 #include "test_iterators.h"

libcxx/test/std/ranges/range.adaptors/range.join.view/iterator/ctor.other.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 // constexpr iterator(iterator<!Const> i)
 //             requires Const &&
 //                      convertible_to<iterator_t<V>, OuterIter> &&
 //                      convertible_to<iterator_t<InnerRng>, InnerIter>;
 
 #include <cassert>
 #include <ranges>

libcxx/test/std/ranges/range.adaptors/range.join.view/iterator/ctor.parent.outer.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 // constexpr iterator(Parent& parent, OuterIter outer);
 
 #include <cassert>
 #include <ranges>
 
 #include "../types.h"
 

libcxx/test/std/ranges/range.adaptors/range.join.view/iterator/decrement.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 // constexpr iterator& operator--();
 //              requires ref-is-glvalue && bidirectional_range<Base> &&
 //                       bidirectional_range<range_reference_t<Base>> &&
 //                       common_range<range_reference_t<Base>>;
 // constexpr iterator operator--(int);
 //              requires ref-is-glvalue && bidirectional_range<Base> &&
 //                       bidirectional_range<range_reference_t<Base>> &&

libcxx/test/std/ranges/range.adaptors/range.join.view/iterator/eq.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 // friend constexpr bool operator==(const iterator& x, const iterator& y);
 //          requires ref-is-glvalue && equality_comparable<iterator_t<Base>> &&
 //                   equality_comparable<iterator_t<range_reference_t<Base>>>;
 
 #include <cassert>
 #include <ranges>
 

libcxx/test/std/ranges/range.adaptors/range.join.view/iterator/increment.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 // constexpr iterator& operator++();
 // constexpr void operator++(int);
 // constexpr iterator operator++(int)
 //            requires ref-is-glvalue && forward_range<Base> &&
 //                     forward_range<range_reference_t<Base>>;
 
 #include <cassert>

libcxx/test/std/ranges/range.adaptors/range.join.view/iterator/iter.move.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 // friend constexpr decltype(auto) iter_move(const iterator& i);
 
 #include <cassert>
 #include <ranges>
 
 #include "../types.h"
 

libcxx/test/std/ranges/range.adaptors/range.join.view/iterator/iter.swap.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 // friend constexpr void iter_swap(const iterator& x, const iterator& y);
 
 #include <cassert>
 #include <ranges>
 
 #include "../types.h"
 

libcxx/test/std/ranges/range.adaptors/range.join.view/iterator/member_types.compile.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 // Iterator traits and member typedefs in join_view::<iterator>.
 
 #include <ranges>
 
 #include "test_iterators.h"
 #include "test_macros.h"
 #include "../types.h"

libcxx/test/std/ranges/range.adaptors/range.join.view/iterator/star.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 // constexpr decltype(auto) operator*() const;
 
 #include <cassert>
 #include <ranges>
 
 #include "test_macros.h"
 #include "../types.h"

libcxx/test/std/ranges/range.adaptors/range.join.view/sentinel/ctor.default.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 // sentinel() = default;
 
 #include <cassert>
 #include <ranges>
 
 #include "test_macros.h"
 #include "../types.h"

libcxx/test/std/ranges/range.adaptors/range.join.view/sentinel/ctor.other.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 // constexpr sentinel(sentinel<!Const> s);
 //             requires Const && convertible_to<sentinel_t<V>, sentinel_t<Base>>;
 
 #include <cassert>
 #include <ranges>
 
 #include "../types.h"

libcxx/test/std/ranges/range.adaptors/range.join.view/sentinel/ctor.parent.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 // constexpr explicit sentinel(Parent& parent);
 
 #include <cassert>
 #include <ranges>
 
 #include "test_macros.h"
 #include "../types.h"

libcxx/test/std/ranges/range.adaptors/range.join.view/sentinel/eq.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 // template<bool OtherConst>
 //   requires sentinel_for<sentinel_t<Base>, iterator_t<maybe-const<OtherConst, V>>>
 // friend constexpr bool operator==(const iterator<OtherConst>& x, const sentinel& y);
 
 #include <cassert>
 #include <concepts>
 #include <functional>