Rename BitSetIterator.h to bitset_utils.h

BUG=angleproject:1814

Change-Id: I152ae13b6b7cf0ba72259967f0f124e199b20e07
Reviewed-on: https://chromium-review.googlesource.com/471826
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>
diff --git a/src/common/bitset_utils_unittest.cpp b/src/common/bitset_utils_unittest.cpp
new file mode 100644
index 0000000..61eff56
--- /dev/null
+++ b/src/common/bitset_utils_unittest.cpp
@@ -0,0 +1,91 @@
+//
+// Copyright 2015 The ANGLE Project Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// bitset_utils_unittest:
+//   Tests bitset helpers and custom classes.
+//
+
+#include <gtest/gtest.h>
+
+#include "common/bitset_utils.h"
+
+using namespace angle;
+
+namespace
+{
+class BitSetIteratorTest : public testing::Test
+{
+  protected:
+    std::bitset<40> mStateBits;
+};
+
+// Simple iterator test.
+TEST_F(BitSetIteratorTest, Iterator)
+{
+    std::set<unsigned long> originalValues;
+    originalValues.insert(2);
+    originalValues.insert(6);
+    originalValues.insert(8);
+    originalValues.insert(35);
+
+    for (unsigned long value : originalValues)
+    {
+        mStateBits.set(value);
+    }
+
+    std::set<unsigned long> readValues;
+    for (unsigned long bit : IterateBitSet(mStateBits))
+    {
+        EXPECT_EQ(1u, originalValues.count(bit));
+        EXPECT_EQ(0u, readValues.count(bit));
+        readValues.insert(bit);
+    }
+
+    EXPECT_EQ(originalValues.size(), readValues.size());
+}
+
+// Test an empty iterator.
+TEST_F(BitSetIteratorTest, EmptySet)
+{
+    // We don't use the FAIL gtest macro here since it returns immediately,
+    // causing an unreachable code warning in MSVS
+    bool sawBit = false;
+    for (unsigned long bit : IterateBitSet(mStateBits))
+    {
+        sawBit = true;
+        UNUSED_VARIABLE(bit);
+    }
+    EXPECT_FALSE(sawBit);
+}
+
+// Test iterating a result of combining two bitsets.
+TEST_F(BitSetIteratorTest, NonLValueBitset)
+{
+    std::bitset<40> otherBits;
+
+    mStateBits.set(1);
+    mStateBits.set(2);
+    mStateBits.set(3);
+    mStateBits.set(4);
+
+    otherBits.set(0);
+    otherBits.set(1);
+    otherBits.set(3);
+    otherBits.set(5);
+
+    std::set<unsigned long> seenBits;
+
+    for (unsigned long bit : IterateBitSet(mStateBits & otherBits))
+    {
+        EXPECT_EQ(0u, seenBits.count(bit));
+        seenBits.insert(bit);
+        EXPECT_TRUE(mStateBits[bit]);
+        EXPECT_TRUE(otherBits[bit]);
+    }
+
+    EXPECT_EQ((mStateBits & otherBits).count(), seenBits.size());
+}
+
+}  // anonymous namespace