Tools/TestWebKitAPI/Tests/WTF/Hasher.cpp - WebKit - Git at Google

 /*
  * Copyright (C) 2017 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  * THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "config.h"

 #include <array>
 #include <limits>
 #include <wtf/Hasher.h>
 #include <wtf/Optional.h>
 #include <wtf/Vector.h>

 namespace TestWebKitAPI {

 // Test against actual hash values.
 // We don't really depend on specific values, but it makes testing simpler.
 // Could instead construct tests that check hashes against each other.
 // No big deal to update all of these if we change the hash algorithm.

 const uint32_t emptyHash = 82610334U;
 const uint32_t zero32BitHash = 242183504U;
 const uint32_t zero64BitHash = 579236260U;
 const uint32_t one32BitHash = 690138192U;
 const uint32_t one64BitHash = 1621454911U;

 TEST(WTF, Hasher_integer)
 {
     EXPECT_EQ(zero32BitHash, computeHash(0U));
     EXPECT_EQ(zero32BitHash, computeHash(false));
     EXPECT_EQ(zero32BitHash, computeHash(static_cast<char>(0)));
     EXPECT_EQ(zero32BitHash, computeHash(static_cast<int8_t>(0)));
     EXPECT_EQ(zero32BitHash, computeHash(static_cast<uint8_t>(0)));
     EXPECT_EQ(zero32BitHash, computeHash(static_cast<int16_t>(0)));
     EXPECT_EQ(zero32BitHash, computeHash(static_cast<uint16_t>(0)));
     EXPECT_EQ(zero32BitHash, computeHash(0));

     EXPECT_EQ(zero64BitHash, computeHash(0ULL));
     EXPECT_EQ(sizeof(long) == sizeof(int32_t) ? zero32BitHash : zero64BitHash, computeHash(0L));
     EXPECT_EQ(sizeof(unsigned long) == sizeof(uint32_t) ? zero32BitHash : zero64BitHash, computeHash(0UL));
     EXPECT_EQ(zero64BitHash, computeHash(0LL));

     EXPECT_EQ(one32BitHash, computeHash(1U));
     EXPECT_EQ(one32BitHash, computeHash(true));
     EXPECT_EQ(one32BitHash, computeHash(static_cast<char>(1)));
     EXPECT_EQ(one32BitHash, computeHash(static_cast<int8_t>(1)));
     EXPECT_EQ(one32BitHash, computeHash(static_cast<uint8_t>(1)));
     EXPECT_EQ(one32BitHash, computeHash(static_cast<int16_t>(1)));
     EXPECT_EQ(one32BitHash, computeHash(static_cast<uint16_t>(1)));
     EXPECT_EQ(one32BitHash, computeHash(1));

     EXPECT_EQ(one64BitHash, computeHash(1ULL));
     EXPECT_EQ(sizeof(long) == sizeof(int32_t) ? one32BitHash : one64BitHash, computeHash(1L));
     EXPECT_EQ(sizeof(unsigned long) == sizeof(uint32_t) ? one32BitHash : one64BitHash, computeHash(1UL));
     EXPECT_EQ(one64BitHash, computeHash(1LL));

     EXPECT_EQ(1772381661U, computeHash(0x7FU));
     EXPECT_EQ(1772381661U, computeHash(std::numeric_limits<int8_t>::max()));

     EXPECT_EQ(3730877340U, computeHash(0x80U));
     EXPECT_EQ(3730877340U, computeHash(std::numeric_limits<int8_t>::min()));

     EXPECT_EQ(376510634U, computeHash(0xFFU));
     EXPECT_EQ(376510634U, computeHash(std::numeric_limits<uint8_t>::max()));
     EXPECT_EQ(376510634U, computeHash(static_cast<char>(-1)));
     EXPECT_EQ(376510634U, computeHash(static_cast<int8_t>(-1)));

     EXPECT_EQ(262632278U, computeHash(0x7FFFU));
     EXPECT_EQ(262632278U, computeHash(std::numeric_limits<int16_t>::max()));

     EXPECT_EQ(2981978661U, computeHash(0x8000U));
     EXPECT_EQ(2981978661U, computeHash(std::numeric_limits<int16_t>::min()));

     EXPECT_EQ(894984179U, computeHash(0xFFFFU));
     EXPECT_EQ(894984179U, computeHash(std::numeric_limits<uint16_t>::max()));
     EXPECT_EQ(894984179U, computeHash(static_cast<int16_t>(-1)));

     EXPECT_EQ(3430670328U, computeHash(0x7FFFFFFFU));
     EXPECT_EQ(3430670328U, computeHash(std::numeric_limits<int32_t>::max()));

     EXPECT_EQ(2425683428U, computeHash(0x80000000U));
     EXPECT_EQ(2425683428U, computeHash(std::numeric_limits<int32_t>::min()));

     EXPECT_EQ(1955511435U, computeHash(0xFFFFFFFFU));
     EXPECT_EQ(1955511435U, computeHash(std::numeric_limits<uint32_t>::max()));
     EXPECT_EQ(1955511435U, computeHash(-1));

     EXPECT_EQ(1264532604U, computeHash(0x8000000000000000ULL));
     EXPECT_EQ(1264532604U, computeHash(std::numeric_limits<int64_t>::min()));
     EXPECT_EQ(sizeof(long) == sizeof(int32_t) ? 2425683428U : 1264532604U, computeHash(std::numeric_limits<long>::min()));

     EXPECT_EQ(2961049834U, computeHash(0x7FFFFFFFFFFFFFFFULL));
     EXPECT_EQ(2961049834U, computeHash(std::numeric_limits<int64_t>::max()));
     EXPECT_EQ(sizeof(long) == sizeof(int32_t) ? 3430670328U : 2961049834U, computeHash(std::numeric_limits<long>::max()));

     EXPECT_EQ(1106332091U, computeHash(0xFFFFFFFFFFFFFFFFULL));
     EXPECT_EQ(1106332091U, computeHash(std::numeric_limits<uint64_t>::max()));
     EXPECT_EQ(sizeof(long) == sizeof(int32_t) ? 1955511435U : 1106332091U, computeHash(std::numeric_limits<unsigned long>::max()));
     EXPECT_EQ(sizeof(long) == sizeof(int32_t) ? 1955511435U : 1106332091U, computeHash(-1L));
     EXPECT_EQ(1106332091U, computeHash(-1LL));
 }

 TEST(WTF, Hasher_floatingPoint)
 {
     EXPECT_EQ(zero64BitHash, computeHash(0.0));
     EXPECT_EQ(1264532604U, computeHash(-0.0)); // Note, not same as hash of 0.0.
     EXPECT_EQ(one64BitHash, computeHash(std::numeric_limits<double>::denorm_min()));

     EXPECT_EQ(2278399980U, computeHash(1.0));
     EXPECT_EQ(3870689297U, computeHash(-1.0));

     EXPECT_EQ(3016344414U, computeHash(std::numeric_limits<double>::min()));
     EXPECT_EQ(1597662982U, computeHash(std::numeric_limits<double>::max()));

     EXPECT_EQ(2501702556U, computeHash(std::numeric_limits<double>::lowest()));
     EXPECT_EQ(2214439802U, computeHash(std::numeric_limits<double>::epsilon()));

     EXPECT_EQ(2678086759U, computeHash(std::numeric_limits<double>::quiet_NaN()));
     EXPECT_EQ(2304445393U, computeHash(std::numeric_limits<double>::infinity()));
     EXPECT_EQ(2232593311U, computeHash(-std::numeric_limits<double>::infinity()));

     EXPECT_EQ(zero32BitHash, computeHash(0.0f));
     EXPECT_EQ(2425683428U, computeHash(-0.0f)); // Note, not same as hash of 0.0f.
     EXPECT_EQ(one32BitHash, computeHash(std::numeric_limits<float>::denorm_min()));

     EXPECT_EQ(1081575966U, computeHash(1.0f));
     EXPECT_EQ(3262093188U, computeHash(-1.0f));

     EXPECT_EQ(3170189524U, computeHash(std::numeric_limits<float>::min()));
     EXPECT_EQ(11021299U, computeHash(std::numeric_limits<float>::max()));

     EXPECT_EQ(3212069506U, computeHash(std::numeric_limits<float>::lowest()));
     EXPECT_EQ(1308784506U, computeHash(std::numeric_limits<float>::epsilon()));

     EXPECT_EQ(2751288511U, computeHash(std::numeric_limits<float>::quiet_NaN()));
     EXPECT_EQ(3457049256U, computeHash(std::numeric_limits<float>::infinity()));
     EXPECT_EQ(4208873971U, computeHash(-std::numeric_limits<float>::infinity()));
 }

 TEST(WTF, Hasher_multiple)
 {
     EXPECT_EQ(emptyHash, computeHash());
     EXPECT_EQ(emptyHash, computeHash(std::make_tuple()));
     EXPECT_EQ(emptyHash, computeHash(std::array<int, 0> { }));
     EXPECT_EQ(emptyHash, computeHash(Vector<int> { }));
     EXPECT_EQ(emptyHash, computeHash(Vector<int, 1> { }));

     EXPECT_EQ(zero32BitHash, computeHash(std::array<int, 1> { { 0 } }));
     EXPECT_EQ(zero32BitHash, computeHash(Vector<int> { 0 }));
     EXPECT_EQ(zero32BitHash, computeHash(Vector<int, 1> { 0 }));
     EXPECT_EQ(zero32BitHash, computeHash(std::optional<int> { std::nullopt }));
     EXPECT_EQ(zero32BitHash, computeHash(std::make_tuple(0)));

     EXPECT_EQ(one64BitHash, computeHash(1, 0));
     EXPECT_EQ(one64BitHash, computeHash(std::make_tuple(1, 0)));
     EXPECT_EQ(one64BitHash, computeHash(std::make_pair(1, 0)));
     EXPECT_EQ(one64BitHash, computeHash(std::array<int, 2> { { 1, 0 } }));
     EXPECT_EQ(one64BitHash, computeHash({ 1, 0 }));
     EXPECT_EQ(one64BitHash, computeHash(std::optional<int> { 0 }));
     EXPECT_EQ(one64BitHash, computeHash(Vector<int> { { 1, 0 } }));
     EXPECT_EQ(one64BitHash, computeHash(Vector<int, 1> { { 1, 0 } }));

     EXPECT_EQ(one64BitHash, computeHash(std::make_tuple(1), std::array<int, 1> { { 0 } }));
     EXPECT_EQ(one64BitHash, computeHash(std::make_tuple(std::make_tuple(1), std::array<int, 1> { { 0 } })));

     EXPECT_EQ(1652352321U, computeHash(1, 2, 3, 4));
     EXPECT_EQ(1652352321U, computeHash(std::make_tuple(1, 2, 3, 4)));
     EXPECT_EQ(1652352321U, computeHash(std::make_pair(std::make_pair(1, 2), std::make_pair(3, 4))));
 }

 struct HasherAddCustom1 { };

 void add(Hasher& hasher, const HasherAddCustom1&)
 {
     add(hasher, 1, 2, 3, 4);
 }

 struct HasherAddCustom2 { };

 void add(Hasher& hasher, const HasherAddCustom2&)
 {
     add(hasher, { 1, 2, 3, 4 });
 }

 TEST(WTF, Hasher_custom)
 {
     EXPECT_EQ(1652352321U, computeHash(HasherAddCustom1 { }));
     EXPECT_EQ(1652352321U, computeHash(HasherAddCustom2 { }));
 }

 #if 0 // FIXME: Add support for tuple-like classes.

 struct HasherAddTupleLikeClass1 {
     std::array<int, 4> array { { 1, 2, 3, 4 } };
     template<size_t i> int get() const { return std::get<i>(array); }
 };

 struct HasherAddTupleLikeClass2 {
     std::array<int, 4> array { { 1, 2, 3, 4 } };
 };

 }

 namespace std {

 // FIXME: Documentation at cppreference.cpp says std::tuple_size is a struct, but it's a class in current macOS tools.
 // FIXME: It's inelegant to inject this into the std namespace. Is that really how a tuple-like class needs to be defined?
 // FIXME: This is so inconvenient that I am not sure it's something we want to do for lots of classes in WebKit.
 template<> class std::tuple_size<TestWebKitAPI::HasherAddTupleLikeClass1> : public std::integral_constant<size_t, std::tuple_size<decltype(TestWebKitAPI::HasherAddTupleLikeClass1::array)>::value> { };

 template<> class std::tuple_size<TestWebKitAPI::HasherAddTupleLikeClass2> : public std::integral_constant<size_t, std::tuple_size<decltype(TestWebKitAPI::HasherAddTupleLikeClass2::array)>::value> { };

 }

 namespace TestWebKitAPI {

 // FIXME: Is it OK for the get to be in the class's namespace and rely on argument-dependent lookup?
 // Or does this function template need to be moved into the std namespace like the tuple_size specialization?
 template<size_t i> int get(const HasherAddTupleLikeClass2& object)
 {
     return get<i>(object.array);
 }

 TEST(WTF, Hasher_tupleLike)
 {
     EXPECT_EQ(1652352321U, computeHash(HasherAddTupleLikeClass1 { }));
     EXPECT_EQ(1652352321U, computeHash(HasherAddTupleLikeClass2 { }));
 }

 #endif

 } // namespace TestWebKitAPI
	/*
	* Copyright (C) 2017 Apple Inc. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
	* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
	* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
	* THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "config.h"

	#include <array>
	#include <limits>
	#include <wtf/Hasher.h>
	#include <wtf/Optional.h>
	#include <wtf/Vector.h>

	namespace TestWebKitAPI {

	// Test against actual hash values.
	// We don't really depend on specific values, but it makes testing simpler.
	// Could instead construct tests that check hashes against each other.
	// No big deal to update all of these if we change the hash algorithm.

	const uint32_t emptyHash = 82610334U;
	const uint32_t zero32BitHash = 242183504U;
	const uint32_t zero64BitHash = 579236260U;
	const uint32_t one32BitHash = 690138192U;
	const uint32_t one64BitHash = 1621454911U;

	TEST(WTF, Hasher_integer)
	{
	EXPECT_EQ(zero32BitHash, computeHash(0U));
	EXPECT_EQ(zero32BitHash, computeHash(false));
	EXPECT_EQ(zero32BitHash, computeHash(static_cast<char>(0)));
	EXPECT_EQ(zero32BitHash, computeHash(static_cast<int8_t>(0)));
	EXPECT_EQ(zero32BitHash, computeHash(static_cast<uint8_t>(0)));
	EXPECT_EQ(zero32BitHash, computeHash(static_cast<int16_t>(0)));
	EXPECT_EQ(zero32BitHash, computeHash(static_cast<uint16_t>(0)));
	EXPECT_EQ(zero32BitHash, computeHash(0));

	EXPECT_EQ(zero64BitHash, computeHash(0ULL));
	EXPECT_EQ(sizeof(long) == sizeof(int32_t) ? zero32BitHash : zero64BitHash, computeHash(0L));
	EXPECT_EQ(sizeof(unsigned long) == sizeof(uint32_t) ? zero32BitHash : zero64BitHash, computeHash(0UL));
	EXPECT_EQ(zero64BitHash, computeHash(0LL));

	EXPECT_EQ(one32BitHash, computeHash(1U));
	EXPECT_EQ(one32BitHash, computeHash(true));
	EXPECT_EQ(one32BitHash, computeHash(static_cast<char>(1)));
	EXPECT_EQ(one32BitHash, computeHash(static_cast<int8_t>(1)));
	EXPECT_EQ(one32BitHash, computeHash(static_cast<uint8_t>(1)));
	EXPECT_EQ(one32BitHash, computeHash(static_cast<int16_t>(1)));
	EXPECT_EQ(one32BitHash, computeHash(static_cast<uint16_t>(1)));
	EXPECT_EQ(one32BitHash, computeHash(1));

	EXPECT_EQ(one64BitHash, computeHash(1ULL));
	EXPECT_EQ(sizeof(long) == sizeof(int32_t) ? one32BitHash : one64BitHash, computeHash(1L));
	EXPECT_EQ(sizeof(unsigned long) == sizeof(uint32_t) ? one32BitHash : one64BitHash, computeHash(1UL));
	EXPECT_EQ(one64BitHash, computeHash(1LL));

	EXPECT_EQ(1772381661U, computeHash(0x7FU));
	EXPECT_EQ(1772381661U, computeHash(std::numeric_limits<int8_t>::max()));

	EXPECT_EQ(3730877340U, computeHash(0x80U));
	EXPECT_EQ(3730877340U, computeHash(std::numeric_limits<int8_t>::min()));

	EXPECT_EQ(376510634U, computeHash(0xFFU));
	EXPECT_EQ(376510634U, computeHash(std::numeric_limits<uint8_t>::max()));
	EXPECT_EQ(376510634U, computeHash(static_cast<char>(-1)));
	EXPECT_EQ(376510634U, computeHash(static_cast<int8_t>(-1)));

	EXPECT_EQ(262632278U, computeHash(0x7FFFU));
	EXPECT_EQ(262632278U, computeHash(std::numeric_limits<int16_t>::max()));

	EXPECT_EQ(2981978661U, computeHash(0x8000U));
	EXPECT_EQ(2981978661U, computeHash(std::numeric_limits<int16_t>::min()));

	EXPECT_EQ(894984179U, computeHash(0xFFFFU));
	EXPECT_EQ(894984179U, computeHash(std::numeric_limits<uint16_t>::max()));
	EXPECT_EQ(894984179U, computeHash(static_cast<int16_t>(-1)));

	EXPECT_EQ(3430670328U, computeHash(0x7FFFFFFFU));
	EXPECT_EQ(3430670328U, computeHash(std::numeric_limits<int32_t>::max()));

	EXPECT_EQ(2425683428U, computeHash(0x80000000U));
	EXPECT_EQ(2425683428U, computeHash(std::numeric_limits<int32_t>::min()));

	EXPECT_EQ(1955511435U, computeHash(0xFFFFFFFFU));
	EXPECT_EQ(1955511435U, computeHash(std::numeric_limits<uint32_t>::max()));
	EXPECT_EQ(1955511435U, computeHash(-1));

	EXPECT_EQ(1264532604U, computeHash(0x8000000000000000ULL));
	EXPECT_EQ(1264532604U, computeHash(std::numeric_limits<int64_t>::min()));
	EXPECT_EQ(sizeof(long) == sizeof(int32_t) ? 2425683428U : 1264532604U, computeHash(std::numeric_limits<long>::min()));

	EXPECT_EQ(2961049834U, computeHash(0x7FFFFFFFFFFFFFFFULL));
	EXPECT_EQ(2961049834U, computeHash(std::numeric_limits<int64_t>::max()));
	EXPECT_EQ(sizeof(long) == sizeof(int32_t) ? 3430670328U : 2961049834U, computeHash(std::numeric_limits<long>::max()));

	EXPECT_EQ(1106332091U, computeHash(0xFFFFFFFFFFFFFFFFULL));
	EXPECT_EQ(1106332091U, computeHash(std::numeric_limits<uint64_t>::max()));
	EXPECT_EQ(sizeof(long) == sizeof(int32_t) ? 1955511435U : 1106332091U, computeHash(std::numeric_limits<unsigned long>::max()));
	EXPECT_EQ(sizeof(long) == sizeof(int32_t) ? 1955511435U : 1106332091U, computeHash(-1L));
	EXPECT_EQ(1106332091U, computeHash(-1LL));
	}

	TEST(WTF, Hasher_floatingPoint)
	{
	EXPECT_EQ(zero64BitHash, computeHash(0.0));
	EXPECT_EQ(1264532604U, computeHash(-0.0)); // Note, not same as hash of 0.0.
	EXPECT_EQ(one64BitHash, computeHash(std::numeric_limits<double>::denorm_min()));

	EXPECT_EQ(2278399980U, computeHash(1.0));
	EXPECT_EQ(3870689297U, computeHash(-1.0));

	EXPECT_EQ(3016344414U, computeHash(std::numeric_limits<double>::min()));
	EXPECT_EQ(1597662982U, computeHash(std::numeric_limits<double>::max()));

	EXPECT_EQ(2501702556U, computeHash(std::numeric_limits<double>::lowest()));
	EXPECT_EQ(2214439802U, computeHash(std::numeric_limits<double>::epsilon()));

	EXPECT_EQ(2678086759U, computeHash(std::numeric_limits<double>::quiet_NaN()));
	EXPECT_EQ(2304445393U, computeHash(std::numeric_limits<double>::infinity()));
	EXPECT_EQ(2232593311U, computeHash(-std::numeric_limits<double>::infinity()));

	EXPECT_EQ(zero32BitHash, computeHash(0.0f));
	EXPECT_EQ(2425683428U, computeHash(-0.0f)); // Note, not same as hash of 0.0f.
	EXPECT_EQ(one32BitHash, computeHash(std::numeric_limits<float>::denorm_min()));

	EXPECT_EQ(1081575966U, computeHash(1.0f));
	EXPECT_EQ(3262093188U, computeHash(-1.0f));

	EXPECT_EQ(3170189524U, computeHash(std::numeric_limits<float>::min()));
	EXPECT_EQ(11021299U, computeHash(std::numeric_limits<float>::max()));

	EXPECT_EQ(3212069506U, computeHash(std::numeric_limits<float>::lowest()));
	EXPECT_EQ(1308784506U, computeHash(std::numeric_limits<float>::epsilon()));

	EXPECT_EQ(2751288511U, computeHash(std::numeric_limits<float>::quiet_NaN()));
	EXPECT_EQ(3457049256U, computeHash(std::numeric_limits<float>::infinity()));
	EXPECT_EQ(4208873971U, computeHash(-std::numeric_limits<float>::infinity()));
	}

	TEST(WTF, Hasher_multiple)
	{
	EXPECT_EQ(emptyHash, computeHash());
	EXPECT_EQ(emptyHash, computeHash(std::make_tuple()));
	EXPECT_EQ(emptyHash, computeHash(std::array<int, 0> { }));
	EXPECT_EQ(emptyHash, computeHash(Vector<int> { }));
	EXPECT_EQ(emptyHash, computeHash(Vector<int, 1> { }));

	EXPECT_EQ(zero32BitHash, computeHash(std::array<int, 1> { { 0 } }));
	EXPECT_EQ(zero32BitHash, computeHash(Vector<int> { 0 }));
	EXPECT_EQ(zero32BitHash, computeHash(Vector<int, 1> { 0 }));
	EXPECT_EQ(zero32BitHash, computeHash(std::optional<int> { std::nullopt }));
	EXPECT_EQ(zero32BitHash, computeHash(std::make_tuple(0)));

	EXPECT_EQ(one64BitHash, computeHash(1, 0));
	EXPECT_EQ(one64BitHash, computeHash(std::make_tuple(1, 0)));
	EXPECT_EQ(one64BitHash, computeHash(std::make_pair(1, 0)));
	EXPECT_EQ(one64BitHash, computeHash(std::array<int, 2> { { 1, 0 } }));
	EXPECT_EQ(one64BitHash, computeHash({ 1, 0 }));
	EXPECT_EQ(one64BitHash, computeHash(std::optional<int> { 0 }));
	EXPECT_EQ(one64BitHash, computeHash(Vector<int> { { 1, 0 } }));
	EXPECT_EQ(one64BitHash, computeHash(Vector<int, 1> { { 1, 0 } }));

	EXPECT_EQ(one64BitHash, computeHash(std::make_tuple(1), std::array<int, 1> { { 0 } }));
	EXPECT_EQ(one64BitHash, computeHash(std::make_tuple(std::make_tuple(1), std::array<int, 1> { { 0 } })));

	EXPECT_EQ(1652352321U, computeHash(1, 2, 3, 4));
	EXPECT_EQ(1652352321U, computeHash(std::make_tuple(1, 2, 3, 4)));
	EXPECT_EQ(1652352321U, computeHash(std::make_pair(std::make_pair(1, 2), std::make_pair(3, 4))));
	}

	struct HasherAddCustom1 { };

	void add(Hasher& hasher, const HasherAddCustom1&)
	{
	add(hasher, 1, 2, 3, 4);
	}

	struct HasherAddCustom2 { };

	void add(Hasher& hasher, const HasherAddCustom2&)
	{
	add(hasher, { 1, 2, 3, 4 });
	}

	TEST(WTF, Hasher_custom)
	{
	EXPECT_EQ(1652352321U, computeHash(HasherAddCustom1 { }));
	EXPECT_EQ(1652352321U, computeHash(HasherAddCustom2 { }));
	}

	#if 0 // FIXME: Add support for tuple-like classes.

	struct HasherAddTupleLikeClass1 {
	std::array<int, 4> array { { 1, 2, 3, 4 } };
	template<size_t i> int get() const { return std::get<i>(array); }
	};

	struct HasherAddTupleLikeClass2 {
	std::array<int, 4> array { { 1, 2, 3, 4 } };
	};

	}

	namespace std {

	// FIXME: Documentation at cppreference.cpp says std::tuple_size is a struct, but it's a class in current macOS tools.
	// FIXME: It's inelegant to inject this into the std namespace. Is that really how a tuple-like class needs to be defined?
	// FIXME: This is so inconvenient that I am not sure it's something we want to do for lots of classes in WebKit.
	template<> class std::tuple_size<TestWebKitAPI::HasherAddTupleLikeClass1> : public std::integral_constant<size_t, std::tuple_size<decltype(TestWebKitAPI::HasherAddTupleLikeClass1::array)>::value> { };

	template<> class std::tuple_size<TestWebKitAPI::HasherAddTupleLikeClass2> : public std::integral_constant<size_t, std::tuple_size<decltype(TestWebKitAPI::HasherAddTupleLikeClass2::array)>::value> { };

	}

	namespace TestWebKitAPI {

	// FIXME: Is it OK for the get to be in the class's namespace and rely on argument-dependent lookup?
	// Or does this function template need to be moved into the std namespace like the tuple_size specialization?
	template<size_t i> int get(const HasherAddTupleLikeClass2& object)
	{
	return get<i>(object.array);
	}

	TEST(WTF, Hasher_tupleLike)
	{
	EXPECT_EQ(1652352321U, computeHash(HasherAddTupleLikeClass1 { }));
	EXPECT_EQ(1652352321U, computeHash(HasherAddTupleLikeClass2 { }));
	}

	#endif

	} // namespace TestWebKitAPI