[libcxx-commits] [PATCH] D96074: [test] std::nth_element regression

[Jordan Rupprecht via Phabricator via libcxx-commits]

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This shows a test case that should pass, but fails, due to a regression in std::nth_element after D93557 <https://reviews.llvm.org/D93557>. The last two elements should be 6 and 7, but they are 7 and 6.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D96074

Files:
  libcxx/test/std/algorithms/alg.sorting/alg.nth.element/nth_element.pass.cpp


Index: libcxx/test/std/algorithms/alg.sorting/alg.nth.element/nth_element.pass.cpp
===================================================================
--- libcxx/test/std/algorithms/alg.sorting/alg.nth.element/nth_element.pass.cpp
+++ libcxx/test/std/algorithms/alg.sorting/alg.nth.element/nth_element.pass.cpp
@@ -47,6 +47,13 @@
         assert(input[4] == 4);
         assert(input[5] + input[6] == 5 + 9);
     }
+
+    {
+      T input[] = {0, 1, 2, 3, 4, 5, 7, 6};
+      std::nth_element(Iter(input), Iter(input + 6), Iter(input + 8));
+      assert(input[6] == 6);
+      assert(input[7] == 7);
+    }
     return true;
 }
 


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