Improve map insertions

util/stdlib/map_insert_test.cc

+// Copyright 2015 The Crashpad Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "util/stdlib/map_insert.h"
+
+#include <string>
+
+#include "gtest/gtest.h"
+
+namespace crashpad {
+namespace test {
+namespace {
+
+TEST(MapInsert, MapInsertOrReplace) {
+  std::map<std::string, int> map;
+  int old_value;
+  EXPECT_TRUE(MapInsertOrReplace(&map, "key", 1, &old_value));
+  std::map<std::string, int> expect_map;
+  expect_map["key"] = 1;
+  EXPECT_EQ(expect_map, map);
+
+  EXPECT_FALSE(MapInsertOrReplace(&map, "key", 2, &old_value));
+  EXPECT_EQ(1, old_value);
+  expect_map["key"] = 2;
+  EXPECT_EQ(expect_map, map);
+
+  EXPECT_TRUE(MapInsertOrReplace(&map, "another", 3, &old_value));
+  expect_map["another"] = 3;
+  EXPECT_EQ(expect_map, map);
+
+  // Make sure nullptr is accepted as old_value.
+  EXPECT_TRUE(MapInsertOrReplace(&map, "yet another", 5, nullptr));
+  expect_map["yet another"] = 5;
+  EXPECT_EQ(expect_map, map);
+
+  EXPECT_FALSE(MapInsertOrReplace(&map, "yet another", 6, nullptr));
+  expect_map["yet another"] = 6;
+  EXPECT_EQ(expect_map, map);
+}
+
+}  // namespace
+}  // namespace test
+}  // namespace crashpad