Add flat_multimap benchmarks

Author: ldionne

libcxx/test/benchmarks/containers/associative/flat_map.bench.cpp

@@ -9,7 +9,6 @@
 // REQUIRES: std-at-least-c++26
 
 #include <flat_map>
-#include <string>
 #include <utility>
 
 #include "associative_container_benchmarks.h"
@@ -18,8 +17,8 @@
 
 template <class K, class V>
 struct support::adapt_operations<std::flat_map<K, V>> {
-  using ValueType = typename std::map<K, V>::value_type;
-  using KeyType   = typename std::map<K, V>::key_type;
+  using ValueType = typename std::flat_map<K, V>::value_type;
+  using KeyType   = typename std::flat_map<K, V>::key_type;
   static ValueType value_from_key(KeyType const& k) { return {k, Generate<V>::arbitrary()}; }
   static KeyType key_from_value(ValueType const& value) { return value.first; }
 

libcxx/test/benchmarks/containers/associative/flat_multimap.bench.cpp

@@ -0,0 +1,35 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// REQUIRES: std-at-least-c++26
+
+#include <flat_map>
+
+#include "associative_container_benchmarks.h"
+#include "../../GenerateInput.h"
+#include "benchmark/benchmark.h"
+
+template <class K, class V>
+struct support::adapt_operations<std::flat_multimap<K, V>> {
+  using ValueType = typename std::flat_multimap<K, V>::value_type;
+  using KeyType   = typename std::flat_multimap<K, V>::key_type;
+  static ValueType value_from_key(KeyType const& k) { return {k, Generate<V>::arbitrary()}; }
+  static KeyType key_from_value(ValueType const& value) { return value.first; }
+
+  using InsertionResult = typename std::flat_multimap<K, V>::iterator;
+  static auto get_iterator(InsertionResult const& result) { return result; }
+};
+
+int main(int argc, char** argv) {
+  support::associative_container_benchmarks<std::flat_multimap<int, int>>("std::flat_multimap<int, int>");
+
+  benchmark::Initialize(&argc, argv);
+  benchmark::RunSpecifiedBenchmarks();
+  benchmark::Shutdown();
+  return 0;
+}