Fixes for _LIBCPP_NODEBUG, std module, and tests

Author: frederick-vs-ja

libcxx/include/__iterator/const_iterator.h

@@ -46,7 +46,7 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 #if _LIBCPP_STD_VER >= 23
 
 template <indirectly_readable _Iter>
-using iter_const_reference_t = common_reference_t<const iter_value_t<_Iter>&&, iter_reference_t<_Iter>>;
+using iter_const_reference_t _LIBCPP_NODEBUG = common_reference_t<const iter_value_t<_Iter>&&, iter_reference_t<_Iter>>;
 
 template <class _Iter>
 concept __constant_iterator = input_iterator<_Iter> && same_as<iter_const_reference_t<_Iter>, iter_reference_t<_Iter>>;
@@ -60,12 +60,12 @@ using const_iterator = conditional_t<__constant_iterator<_Iter>, _Iter, basic_co
 // This doesn't use `conditional_t` to avoid instantiating const_iterator<_Sent> when _Sent is not an input_iterator.
 template <class _Sent>
 struct __const_sentinel_impl {
-  using type = _Sent;
+  using type _LIBCPP_NODEBUG = _Sent;
 };
 template <class _Sent>
   requires input_iterator<_Sent>
 struct __const_sentinel_impl<_Sent> {
-  using type = const_iterator<_Sent>;
+  using type _LIBCPP_NODEBUG = const_iterator<_Sent>;
 };
 template <semiregular _Sent>
 using const_sentinel = __const_sentinel_impl<_Sent>::type;
@@ -104,8 +104,8 @@ template <input_iterator _Iter>
 class _LIBCPP_TEMPLATE_VIS basic_const_iterator : public __basic_const_iterator_category<_Iter> {
   _Iter __current_ = _Iter();
 
-  using __reference        = iter_const_reference_t<_Iter>;
-  using __rvalue_reference = __iter_const_rvalue_reference_t<_Iter>;
+  using __reference _LIBCPP_NODEBUG        = iter_const_reference_t<_Iter>;
+  using __rvalue_reference _LIBCPP_NODEBUG = __iter_const_rvalue_reference_t<_Iter>;
 
 public:
   using value_type      = iter_value_t<_Iter>;
@@ -322,17 +322,17 @@ class _LIBCPP_TEMPLATE_VIS basic_const_iterator : public __basic_const_iterator_
 template <class _Type1, common_with<_Type1> _Type2>
   requires input_iterator<common_type_t<_Type1, _Type2>>
 struct common_type<basic_const_iterator<_Type1>, _Type2> {
-  using type = basic_const_iterator<common_type_t<_Type1, _Type2>>;
+  using type _LIBCPP_NODEBUG = basic_const_iterator<common_type_t<_Type1, _Type2>>;
 };
 template <class _Type1, common_with<_Type1> _Type2>
   requires input_iterator<common_type_t<_Type1, _Type2>>
 struct common_type<_Type2, basic_const_iterator<_Type1>> {
-  using type = basic_const_iterator<common_type_t<_Type1, _Type2>>;
+  using type _LIBCPP_NODEBUG = basic_const_iterator<common_type_t<_Type1, _Type2>>;
 };
 template <class _Type1, common_with<_Type1> _Type2>
   requires input_iterator<common_type_t<_Type1, _Type2>>
 struct common_type<basic_const_iterator<_Type1>, basic_const_iterator<_Type2>> {
-  using type = basic_const_iterator<common_type_t<_Type1, _Type2>>;
+  using type _LIBCPP_NODEBUG = basic_const_iterator<common_type_t<_Type1, _Type2>>;
 };
 
 template <input_iterator _Iter>

libcxx/include/__ranges/const_access.h

@@ -53,7 +53,7 @@ namespace __cbegin {
 struct __fn {
 #  if _LIBCPP_STD_VER >= 23
   template <class _Rng>
-  using _UType = decltype(ranges::begin(ranges::__possibly_const_range(std::declval<_Rng&>())));
+  using _UType _LIBCPP_NODEBUG = decltype(ranges::begin(ranges::__possibly_const_range(std::declval<_Rng&>())));
 
   template <__const_accessible_range _Rng>
   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr static auto operator()(_Rng&& __rng) noexcept(
@@ -100,7 +100,7 @@ namespace __cend {
 struct __fn {
 #  if _LIBCPP_STD_VER >= 23
   template <class _Rng>
-  using _UType = decltype(ranges::end(ranges::__possibly_const_range(std::declval<_Rng&>())));
+  using _UType _LIBCPP_NODEBUG = decltype(ranges::end(ranges::__possibly_const_range(std::declval<_Rng&>())));
 
   template <__const_accessible_range _Rng>
   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr static auto operator()(_Rng&& __rng) noexcept(
@@ -147,7 +147,7 @@ namespace __crbegin {
 struct __fn {
 #  if _LIBCPP_STD_VER >= 23
   template <class _Rng>
-  using _UType = decltype(ranges::rbegin(ranges::__possibly_const_range(std::declval<_Rng&>())));
+  using _UType _LIBCPP_NODEBUG = decltype(ranges::rbegin(ranges::__possibly_const_range(std::declval<_Rng&>())));
 
   template <__const_accessible_range _Rng>
   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr static auto operator()(_Rng&& __rng) noexcept(
@@ -186,7 +186,7 @@ namespace __crend {
 struct __fn {
 #  if _LIBCPP_STD_VER >= 23
   template <class _Rng>
-  using _UType = decltype(ranges::rend(ranges::__possibly_const_range(std::declval<_Rng&>())));
+  using _UType _LIBCPP_NODEBUG = decltype(ranges::rend(ranges::__possibly_const_range(std::declval<_Rng&>())));
 
   template <__const_accessible_range _Rng>
   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr static auto operator()(_Rng&& __rng) noexcept(

libcxx/modules/std/ranges.inc

@@ -265,14 +265,15 @@ export namespace std {
       using std::ranges::views::reverse;
     } // namespace views
 
+#if _LIBCPP_STD_VER >= 23
     // [range.as.const], as const view
-#if 0
     using std::ranges::as_const_view;
 
     namespace views {
       using std::ranges::views::as_const;
     } // namespace views
-#endif
+#endif // _LIBCPP_STD_VER >= 23
+
     // [range.elements], elements view
     using std::ranges::elements_view;
 

libcxx/test/std/containers/views/views.span/span.iterators/rend.pass.cpp

@@ -19,7 +19,7 @@
 #include "test_macros.h"
 
 template <class Span, class Iter>
-constexpr bool testSpanImpl(Span s, Iter rlast) {
+constexpr void testSpanImpl(Span s, Iter rlast) {
   if (s.empty()) {
     assert(rlast == s.rbegin());
   } else {