2 files changed, 32 insertions, 0 deletions
diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges
index fd290ea..25d2e28 100644
--- a/libstdc++-v3/include/std/ranges
+++ b/libstdc++-v3/include/std/ranges
@@ -65,6 +65,7 @@
 #define __glibcxx_want_ranges_chunk
 #define __glibcxx_want_ranges_chunk_by
 #define __glibcxx_want_ranges_enumerate
+#define __glibcxx_want_ranges_indices
 #define __glibcxx_want_ranges_join_with
 #define __glibcxx_want_ranges_repeat
 #define __glibcxx_want_ranges_slide
@@ -785,6 +786,18 @@ namespace views
   };
 
   inline constexpr _Iota iota{};
+
+#ifdef __cpp_lib_ranges_indices // C++ >= 26
+  struct _Indices
+  {
+    template<ranges::__detail::__is_integer_like _Tp>
+      [[nodiscard]] constexpr auto
+      operator() (_Tp __e) const noexcept
+      { return iota(_Tp{}, __e); }
+  };
+
+  inline constexpr _Indices indices{};
+#endif // __cpp_lib_ranges_indices
 } // namespace views
 
 #if _GLIBCXX_HOSTED
diff --git a/libstdc++-v3/include/std/utility b/libstdc++-v3/include/std/utility
index 8a85ccf..3ae1852 100644
--- a/libstdc++-v3/include/std/utility
+++ b/libstdc++-v3/include/std/utility
@@ -98,6 +98,7 @@
 #define __glibcxx_want_tuple_element_t
 #define __glibcxx_want_tuples_by_type
 #define __glibcxx_want_unreachable
+#define __glibcxx_want_observable_checkpoint
 #define __glibcxx_want_tuple_like
 #define __glibcxx_want_constrained_equality
 #include <bits/version.h>
@@ -234,6 +235,24 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   }
 #endif
 
+
+#ifdef __cpp_lib_observable_checkpoint // C++ >= 26
+  /// Informs the compiler that prior actions are considered observable.
+  /**
+   * This may be used to limit the extent to which optimisations based on the
+   * assumed unreachability of undefined behaviour can propagate to earlier
+   * code.
+   *
+   * @since C++26
+   */
+  [[__gnu__::__always_inline__]]
+  inline void
+  observable_checkpoint() noexcept
+  {
+    return __builtin_observable_checkpoint();
+  }
+#endif
+
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace