Add methods for hashing pairs of integer values.

base/hash_tables_unittest.cc

Index: base/hash_tables_unittest.cc
diff --git a/base/hash_tables_unittest.cc b/base/hash_tables_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..27a35d93575f0d2ef702764dacfc995ff0f6db6d
--- /dev/null
+++ b/base/hash_tables_unittest.cc
@@ -0,0 +1,60 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/hash_tables.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+class HashTablesTest : public testing::Test {
+};
+
+#define INSERT_TEST(Type, value1, value2) \
+  { \
+    Type pair(value1, value2); \
+    base::hash_map<Type, int> map; \
+    map[pair] = 1; \
+  }
+
+// Verify that a hash_map can be constructed for pairs of integers of various
+// sizes.
+TEST_F(HashTablesTest, IntegerPairs) {
+  typedef std::pair<short, short> ShortShortPair;
+  typedef std::pair<short, int> ShortIntPair;
+  typedef std::pair<short, int32> ShortInt32Pair;
+  typedef std::pair<short, int64> ShortInt64Pair;
+
+  INSERT_TEST(ShortShortPair, 4, 6);
+  INSERT_TEST(ShortIntPair, 7, (1 << 30) + 4342);
+  INSERT_TEST(ShortInt32Pair, 9, (1 << 29) + 378128932);
+  INSERT_TEST(ShortInt64Pair, 10, (1LL << 60) + 78931732321);
+
+  typedef std::pair<int, short> IntShortPair;
+  typedef std::pair<int, int> IntIntPair;
+  typedef std::pair<int, int32> IntInt32Pair;
+  typedef std::pair<int, int64> IntInt64Pair;
+
+  INSERT_TEST(IntShortPair, 4, 6);
+  INSERT_TEST(IntIntPair, 7, (1 << 30) + 4342);
+  INSERT_TEST(IntInt32Pair, 9, (1 << 29) + 378128932);
+  INSERT_TEST(IntInt64Pair, 10, (1LL << 60) + 78931732321);
+
+  typedef std::pair<int32, short> Int32ShortPair;
+  typedef std::pair<int32, int> Int32IntPair;
+  typedef std::pair<int32, int32> Int32Int32Pair;
+  typedef std::pair<int32, int64> Int32Int64Pair;
+
+  INSERT_TEST(Int32ShortPair, 4, 6);
+  INSERT_TEST(Int32IntPair, 7, (1 << 30) + 4342);
+  INSERT_TEST(Int32Int32Pair, 9, (1 << 29) + 378128932);
+  INSERT_TEST(Int32Int64Pair, 10, (1LL << 60) + 78931732321);
+
+  typedef std::pair<int64, short> Int64ShortPair;
+  typedef std::pair<int64, int> Int64IntPair;
+  typedef std::pair<int64, int32> Int64Int32Pair;
+  typedef std::pair<int64, int64> Int64Int64Pair;
+
+  INSERT_TEST(Int64ShortPair, 4, 6);
+  INSERT_TEST(Int64IntPair, 7, (1 << 30) + 4342);
+  INSERT_TEST(Int64Int32Pair, 9, (1 << 29) + 378128932);
+  INSERT_TEST(Int64Int64Pair, 10, (1LL << 60) + 78931732321);
+}