[libcxx-commits] [libcxx] [libc++][mdspan] P3383R3: mdspan.at() (PR #175213)

[via libcxx-commits]

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@@ -335,4 +335,80 @@ class always_convertible_layout::mapping {
   index_type offset_{};
   index_type scaling_{};
 };
+
+struct SpyIndex {
+  int val;
+  constexpr SpyIndex(int v) : val(v) {}
+  constexpr operator int() const noexcept { return val; }
+};
+
+class strict_cast_layout {
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eiytoq wrote:

These definitions are not reused in this file, but they are intended for future tests related to LWG3974 in `index_operator.pass.cpp`. 

https://github.com/llvm/llvm-project/pull/175213