| /* |
| * Copyright (C) 2013 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. |
| */ |
| |
| #ifndef MoveOnly_h |
| #define MoveOnly_h |
| |
| #include <wtf/HashFunctions.h> |
| #include <wtf/HashTraits.h> |
| |
| class MoveOnly { |
| public: |
| MoveOnly() |
| : m_value(0) |
| { |
| } |
| |
| MoveOnly(unsigned value) |
| : m_value(value) |
| { |
| } |
| |
| unsigned value() const |
| { |
| return m_value; |
| } |
| |
| unsigned operator()() const |
| { |
| return m_value; |
| } |
| |
| MoveOnly(MoveOnly&& other) |
| : m_value(other.m_value) |
| { |
| other.m_value = 0; |
| } |
| |
| MoveOnly& operator=(MoveOnly&& other) |
| { |
| if (this == &other) |
| return *this; |
| |
| m_value = other.m_value; |
| other.m_value = 0; |
| return *this; |
| } |
| |
| friend bool operator==(const MoveOnly& a, const MoveOnly& b) |
| { |
| return a.m_value == b.m_value; |
| } |
| |
| private: |
| unsigned m_value; |
| }; |
| |
| namespace WTF { |
| |
| template<> struct HashTraits<MoveOnly> : public GenericHashTraits<MoveOnly> { |
| static void constructDeletedValue(MoveOnly& slot) { slot = MoveOnly(std::numeric_limits<unsigned>::max()); } |
| static bool isDeletedValue(const MoveOnly& slot) { return slot.value() == std::numeric_limits<unsigned>::max(); } |
| }; |
| |
| template<> struct DefaultHash<MoveOnly> { |
| static unsigned hash(const MoveOnly& key) |
| { |
| return intHash(key.value()); |
| } |
| |
| static bool equal(const MoveOnly& a, const MoveOnly& b) |
| { |
| return a == b; |
| } |
| |
| static const bool safeToCompareToEmptyOrDeleted = true; |
| }; |
| } // namespace WTF |
| |
| #endif // MoveOnly_h |