[libcxx-commits] [libcxx] [libc++][hardening] Don't trigger redundant checks in the fast mode. (PR #77176)

[Louis Dionne via libcxx-commits]

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@@ -152,8 +152,9 @@ class layout_left::mapping {
     // return a value exceeding required_span_size(), which is used to know how large an allocation one needs
     // Thus, this is a canonical point in multi-dimensional data structures to make invalid element access checks
     // However, mdspan does check this on its own, so for now we avoid double checking in hardened mode
-    _LIBCPP_ASSERT_UNCATEGORIZED(__mdspan_detail::__is_multidimensional_index_in(__extents_, __idx...),
-                                 "layout_left::mapping: out of bounds indexing");
+    _LIBCPP_REDUNDANT_ASSERTION( //
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ldionne wrote:

I think what you did is the right call. It seems more likely to me that `mdspan` is used with a custom mapping than a mapping being used with another data structure.

https://github.com/llvm/llvm-project/pull/77176