Merge branch 'main' into users/joker-eph-python-bindings-maintainersusers/joker-eph-python-bindings-maintainers

3 files changed, 34 insertions, 12 deletions

diff --git a/libcxx/include/__ranges/iota_view.h b/libcxx/include/__ranges/iota_view.h
index 4b84585258b9..32ff3408e54e 100644
--- a/libcxx/include/__ranges/iota_view.h
+++ b/libcxx/include/__ranges/iota_view.h
@@ -30,6 +30,7 @@
 #include <__ranges/movable_box.h>
 #include <__ranges/view_interface.h>
 #include <__type_traits/conditional.h>
+#include <__type_traits/decay.h>
 #include <__type_traits/is_nothrow_constructible.h>
 #include <__type_traits/make_unsigned.h>
 #include <__type_traits/type_identity.h>
@@ -374,10 +375,10 @@ namespace views {
 namespace __iota {
 struct __fn {
   template <class _Start>
+    requires(requires(_Start __s) { ranges::iota_view<decay_t<_Start>>(std::forward<_Start>(__s)); })
   _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Start&& __start) const
-      noexcept(noexcept(ranges::iota_view(std::forward<_Start>(__start))))
-          -> decltype(ranges::iota_view(std::forward<_Start>(__start))) {
-    return ranges::iota_view(std::forward<_Start>(__start));
+      noexcept(noexcept(ranges::iota_view<decay_t<_Start>>(std::forward<_Start>(__start)))) {
+    return ranges::iota_view<decay_t<_Start>>(std::forward<_Start>(__start));
   }
 
   template <class _Start, class _BoundSentinel>
diff --git a/libcxx/include/__tree b/libcxx/include/__tree
index 6dadd0915c98..2d8925030ccc 100644
--- a/libcxx/include/__tree
+++ b/libcxx/include/__tree
@@ -47,6 +47,30 @@
 _LIBCPP_PUSH_MACROS
 #include <__undef_macros>
 
+_LIBCPP_DIAGNOSTIC_PUSH
+// GCC complains about the backslashes at the end, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121528
+_LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wcomment")
+// __tree is a red-black-tree implementation used for the associative containers (i.e. (multi)map/set). It stores
+// - (1) a pointer to the node with the smallest (i.e. leftmost) element, namely __begin_node_
+// - (2) the number of nodes in the tree, namely __size_
+// - (3) a pointer to the root of the tree, namely __end_node_
+//
+// Storing (1) and (2) is required to allow for constant time lookups. A tree looks like this in memory:
+//
+//      __end_node_
+//           |
+//          root
+//         /    \
+//       l1       r1
+//      /  \     /  \
+//    ...  ... ...  ...
+//
+// All nodes except __end_node_ have a __left_ and __right_ pointer as well as a __parent_ pointer.
+// __end_node_ only contains a __left_ pointer, which points to the root of the tree.
+// This layout allows for iteration through the tree without a need for special handling of the end node. See
+// __tree_next_iter and __tree_prev_iter for more details.
+_LIBCPP_DIAGNOSTIC_POP
+
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _Pointer>
@@ -167,6 +191,11 @@ _LIBCPP_HIDE_FROM_ABI _NodePtr __tree_next(_NodePtr __x) _NOEXCEPT {
   return __x->__parent_unsafe();
 }
 
+// __tree_next_iter and __tree_prev_iter implement iteration through the tree. The order is as follows:
+// left sub-tree -> node -> right sub-tree. When the right-most node of a sub-tree is reached, we walk up the tree until
+// we find a node where we were in the left sub-tree. We are _always_ in a left sub-tree, since the __end_node_ points
+// to the actual root of the tree through a __left_ pointer. Incrementing the end() pointer is UB, so we can assume that
+// never happens.
 template <class _EndNodePtr, class _NodePtr>
 inline _LIBCPP_HIDE_FROM_ABI _EndNodePtr __tree_next_iter(_NodePtr __x) _NOEXCEPT {
   _LIBCPP_ASSERT_INTERNAL(__x != nullptr, "node shouldn't be null");
diff --git a/libcxx/include/string_view b/libcxx/include/string_view
index f86b2722aca6..9a20bb6f4a0b 100644
--- a/libcxx/include/string_view
+++ b/libcxx/include/string_view
@@ -320,7 +320,7 @@ public:
   _LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI basic_string_view(const _CharT* __s, size_type __len) _NOEXCEPT
       _LIBCPP_DIAGNOSE_NULLPTR_IF(__len != 0 && __s == nullptr, " if len is not zero")
       : __data_(__s), __size_(__len) {
-#  if _LIBCPP_STD_VER >= 14
+#  if !defined(_LIBCPP_CXX03_LANG) && (!defined(_LIBCPP_COMPILER_GCC) || _LIBCPP_STD_VER >= 14)
     // Allocations must fit in `ptrdiff_t` for pointer arithmetic to work. If `__len` exceeds it, the input
     // range could not have been valid. Most likely the caller underflowed some arithmetic and inadvertently
     // passed in a negative length.
@@ -502,7 +502,6 @@ public:
   // find
   _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
   find(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT {
-    _LIBCPP_ASSERT_NON_NULL(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): received nullptr");
     return std::__str_find<value_type, size_type, traits_type, npos>(data(), size(), __s.data(), __pos, __s.size());
   }
 
@@ -527,7 +526,6 @@ public:
   // rfind
   _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
   rfind(basic_string_view __s, size_type __pos = npos) const _NOEXCEPT {
-    _LIBCPP_ASSERT_NON_NULL(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): received nullptr");
     return std::__str_rfind<value_type, size_type, traits_type, npos>(data(), size(), __s.data(), __pos, __s.size());
   }
 
@@ -553,7 +551,6 @@ public:
   // find_first_of
   _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
   find_first_of(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT {
-    _LIBCPP_ASSERT_NON_NULL(__s.size() == 0 || __s.data() != nullptr, "string_view::find_first_of(): received nullptr");
     return std::__str_find_first_of<value_type, size_type, traits_type, npos>(
         data(), size(), __s.data(), __pos, __s.size());
   }
@@ -580,7 +577,6 @@ public:
   // find_last_of
   _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
   find_last_of(basic_string_view __s, size_type __pos = npos) const _NOEXCEPT {
-    _LIBCPP_ASSERT_NON_NULL(__s.size() == 0 || __s.data() != nullptr, "string_view::find_last_of(): received nullptr");
     return std::__str_find_last_of<value_type, size_type, traits_type, npos>(
         data(), size(), __s.data(), __pos, __s.size());
   }
@@ -607,8 +603,6 @@ public:
   // find_first_not_of
   _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
   find_first_not_of(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT {
-    _LIBCPP_ASSERT_NON_NULL(
-        __s.size() == 0 || __s.data() != nullptr, "string_view::find_first_not_of(): received nullptr");
     return std::__str_find_first_not_of<value_type, size_type, traits_type, npos>(
         data(), size(), __s.data(), __pos, __s.size());
   }
@@ -635,8 +629,6 @@ public:
   // find_last_not_of
   _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
   find_last_not_of(basic_string_view __s, size_type __pos = npos) const _NOEXCEPT {
-    _LIBCPP_ASSERT_NON_NULL(
-        __s.size() == 0 || __s.data() != nullptr, "string_view::find_last_not_of(): received nullptr");
     return std::__str_find_last_not_of<value_type, size_type, traits_type, npos>(
         data(), size(), __s.data(), __pos, __s.size());
   }