[libcxx-commits] [libcxx] [libc++] [sort] Improve performance of std::sort (PR #76616)

[Christopher Di Bella via libcxx-commits]

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@@ -68,8 +68,7 @@ void test_same() {
   auto snapshot_custom_v = v;
   std::sort(v.begin(), v.end());
   std::sort(snapshot_v.begin(), snapshot_v.end());
-  std::sort(snapshot_custom_v.begin(), snapshot_custom_v.end(),
-            [](const EqualType&, const EqualType&) { return false; });
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cjdb wrote:

It's worth noting that this is in `test/libcxx`, not `test/std`, and so there's more lenience for tests that are coupled with the implementation. I do think that we should avoid this practice though.

It's also worth noting that this lambda doesn't meet the requirements of `Compare` because it doesn't impose a [strict weak order](https://eel.is/c++draft/algorithms#alg.sorting.general-4) on its elements, so replacing it with something that does is a good idea.

https://github.com/llvm/llvm-project/pull/76616