[libcxx][ranges] Move `namespace views` into `namespace ranges` and add an alias.

[zoecarver]

libcxx/test/std/ranges/range.adaptors/range.all/all.pass.cpp

90

Intentionally testing this inconsistently so that we cover both std::ranges::views and std::views.

[cjdb]

LGTM! Please add a test to make sure that std::views::X is the same as std::ranges::views::X before committing.

[• Quuxplusone]

libcxx/include/__ranges/all.h

35–36

Any appetite for namespace ranges::views { here? I have a slight preference for it, but won't push hard for it right now.

libcxx/test/std/ranges/range.adaptors/range.all/all.pass.cpp

90

I don't particularly object, because I probably wouldn't have noticed if the test had been committed this way to begin with. But if you want to test that std::views is the same as std::ranges::views, the right place for that test is not semi-accidentally inside all.pass.cpp; it may deserve a dedicated test file.
(However, IMHO it also doesn't need a test of its own, because it's super obvious.)

[zoecarver]

libcxx/include/__ranges/all.h

35–36

Good idea. Done.

libcxx/test/std/ranges/range.adaptors/range.all/all.pass.cpp

90

I updated these to have a specific test in the same file.

libcxx/include/__ranges/all.h

 
 _LIBCPP_PUSH_MACROS
 #include <__undef_macros>
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 #if !defined(_LIBCPP_HAS_NO_RANGES)
 
-namespace views {
+namespace ranges::views {
 
 namespace __all {
   struct __fn {
     template<class _Tp>
       requires ranges::view<decay_t<_Tp>>
     _LIBCPP_HIDE_FROM_ABI
     constexpr auto operator()(_Tp&& __t) const
       noexcept(noexcept(_VSTD::__decay_copy(_VSTD::forward<_Tp>(__t))))
     {

 
 inline namespace __cpo {
   inline constexpr auto all = __all::__fn{};
 } // namespace __cpo
 
 template<ranges::viewable_range _Range>
 using all_t = decltype(views::all(declval<_Range>()));
 
-} // namespace views
+} // namespace ranges::views
 
 #endif // !defined(_LIBCPP_HAS_NO_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
 _LIBCPP_POP_MACROS
 
 #endif // _LIBCPP___RANGES_ALL_H

libcxx/include/__ranges/counted.h

 
 _LIBCPP_PUSH_MACROS
 #include <__undef_macros>
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 #if !defined(_LIBCPP_HAS_NO_RANGES)
 
-namespace views {
+namespace ranges::views {
 
 namespace __counted {
   template<class _From, class _To>
   concept __explicitly_convertible = requires {
     _To(_From{});
   };
 
   struct __fn {
struct __fn {
     }
   };
 }
 
 inline namespace __cpo {
   inline constexpr auto counted = __counted::__fn{};
 } // namespace __cpo
 
-} // namespace views
+} // namespace ranges::views
 
 #endif // !defined(_LIBCPP_HAS_NO_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
 _LIBCPP_POP_MACROS
 
 #endif // _LIBCPP___RANGES_COUNTED_H

libcxx/include/__ranges/iota_view.h

//       }
 
   template<class _Start, class _Bound>
     requires (!__integer_like<_Start> || !__integer_like<_Bound> ||
               (__signed_integer_like<_Start> == __signed_integer_like<_Bound>))
   iota_view(_Start, _Bound) -> iota_view<_Start, _Bound>;
 
   template<class _Start, class _Bound>
   inline constexpr bool enable_borrowed_range<iota_view<_Start, _Bound>> = true;
-} // namespace ranges
 
 namespace views {
 namespace __iota {
   struct __fn {
     template<class _Start>
     _LIBCPP_HIDE_FROM_ABI
     constexpr auto operator()(_Start&& __start) const
       noexcept(noexcept(ranges::iota_view(_VSTD::forward<_Start>(__start))))
struct __fn {
     }
   };
 } // namespace __iota
 
 inline namespace __cpo {
   inline constexpr auto iota = __iota::__fn{};
 }
 } // namespace views
+} // namespace ranges
 
 #endif // !defined(_LIBCPP_HAS_NO_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP___RANGES_IOTA_VIEW_H

libcxx/include/ranges

 
 _LIBCPP_PUSH_MACROS
 #include <__undef_macros>
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 #if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_RANGES)
 
+namespace views = ranges::views;
+
 #endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
 _LIBCPP_POP_MACROS
 
 #endif // !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 #endif // _LIBCPP_RANGES

libcxx/test/std/ranges/range.adaptors/range.all/all.pass.cpp

 };
 template<>
 inline constexpr bool std::ranges::enable_borrowed_range<RandomAccessRange> = true;
 
 constexpr bool test() {
   {
     ASSERT_SAME_TYPE(decltype(std::views::all(View<true>())), View<true>);
     static_assert(noexcept(std::views::all(View<true>())));
     static_assert(!noexcept(std::views::all(View<false>())));
 
     auto viewCopy = std::views::all(View<true>(2));
     ASSERT_SAME_TYPE(decltype(viewCopy), View<true>);
     assert(std::ranges::begin(viewCopy) == globalBuff + 2);
     assert(std::ranges::end(viewCopy) == globalBuff + 8);
   }
 
   {
constexpr bool test() {
   {
     auto subrange = std::views::all(RandomAccessRange());
     ASSERT_SAME_TYPE(decltype(subrange),
                      std::ranges::subrange<random_access_iterator<int*>, RandomAccessRange::sentinel>);
     assert(std::ranges::begin(subrange).base() == globalBuff);
     assert(std::ranges::end(subrange) == std::ranges::begin(subrange) + 8);
   }
 
+  {
+    static_assert(std::same_as<decltype(std::views::all), decltype(std::ranges::views::all)>);
+  }
+
   return true;
 }
 
 int main(int, char**) {
   test();
   static_assert(test());
 
   return 0;
 }

libcxx/test/std/ranges/range.adaptors/range.counted/counted.pass.cpp

static_assert(std::semiregular<std::remove_const_t<decltype(std::views::counted)>>);
 
       ASSERT_SAME_TYPE(decltype(std::views::counted(cpp20_input_iterator<int*>(buffer), 8)),
                        std::ranges::subrange<
                          std::counted_iterator<cpp20_input_iterator<int*>>,
                          std::default_sentinel_t>);
     }
   }
 
+  {
+    static_assert(std::same_as<decltype(std::views::counted), decltype(std::ranges::views::counted)>);
+  }
+
   return true;
 }
 
 int main(int, char**) {
   test();
   static_assert(test());
 
   return 0;
 }

libcxx/test/std/ranges/range.factories/range.iota.view/views_iota.pass.cpp

constexpr bool test() {
   testType<unsigned short>(IntComparableWith<unsigned short>(10));
 
   {
     static_assert( std::is_invocable_v<decltype(std::views::iota), int>);
     static_assert(!std::is_invocable_v<decltype(std::views::iota), X>);
     static_assert( std::is_invocable_v<decltype(std::views::iota), int, int>);
     static_assert(!std::is_invocable_v<decltype(std::views::iota), int, X>);
   }
+  {
+    static_assert(std::same_as<decltype(std::views::iota), decltype(std::ranges::views::iota)>);
+  }
 
   return true;
 }
 
 int main(int, char**) {
   test();
   static_assert(test());
 
   return 0;
 }