[libcxx-commits] [libcxx] [libc++] Add benchmarks to the associative containers that don't go to the end of the container (PR #175005)

[Nikolas Klauser via libcxx-commits]

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@@ -340,11 +351,20 @@ void associative_container_benchmarks(std::string container) {
       }
     });
 
-    bench("insert_or_assign(key, value) (new value)", [=](auto& st) {
+    auto insert_or_assign_bench = [=](bool bench_end_iter, auto& st) {
       const std::size_t size = st.range(0);
       std::vector<Value> in  = make_value_types(generate_unique_keys(size + 1));
-      Value to_insert        = in.back();
-      in.pop_back();
+      auto skipped_val       = bench_end_iter ? in.size() - 1 : in.size() / 2;
+      Value to_insert        = in[skipped_val];
+      { // Remove the element
+        std::vector<Value> tmp;
+        tmp.reserve(in.size() - 1);
+        for (size_t i = 0; i != in.size(); ++i)
+          if (i != skipped_val)
+            tmp.emplace_back(in[i]);
+        in = std::move(tmp);
+      }
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philnik777 wrote:

That doesn't work because our elements aren't always Cpp17MoveAssignable. Same below.

https://github.com/llvm/llvm-project/pull/175005