| /**************************************************************************** |
| ** |
| ** Copyright (C) 2016 The Qt Company Ltd. |
| ** Copyright (C) 2015 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Marc Mutz <marc.mutz@kdab.com> |
| ** Contact: https://www.qt.io/licensing/ |
| ** |
| ** This file is part of the QtCore module of the Qt Toolkit. |
| ** |
| ** $QT_BEGIN_LICENSE:LGPL$ |
| ** Commercial License Usage |
| ** Licensees holding valid commercial Qt licenses may use this file in |
| ** accordance with the commercial license agreement provided with the |
| ** Software or, alternatively, in accordance with the terms contained in |
| ** a written agreement between you and The Qt Company. For licensing terms |
| ** and conditions see https://www.qt.io/terms-conditions. For further |
| ** information use the contact form at https://www.qt.io/contact-us. |
| ** |
| ** GNU Lesser General Public License Usage |
| ** Alternatively, this file may be used under the terms of the GNU Lesser |
| ** General Public License version 3 as published by the Free Software |
| ** Foundation and appearing in the file LICENSE.LGPL3 included in the |
| ** packaging of this file. Please review the following information to |
| ** ensure the GNU Lesser General Public License version 3 requirements |
| ** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. |
| ** |
| ** GNU General Public License Usage |
| ** Alternatively, this file may be used under the terms of the GNU |
| ** General Public License version 2.0 or (at your option) the GNU General |
| ** Public license version 3 or any later version approved by the KDE Free |
| ** Qt Foundation. The licenses are as published by the Free Software |
| ** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 |
| ** included in the packaging of this file. Please review the following |
| ** information to ensure the GNU General Public License requirements will |
| ** be met: https://www.gnu.org/licenses/gpl-2.0.html and |
| ** https://www.gnu.org/licenses/gpl-3.0.html. |
| ** |
| ** $QT_END_LICENSE$ |
| ** |
| ****************************************************************************/ |
| |
| #ifndef QHASHFUNCTIONS_H |
| #define QHASHFUNCTIONS_H |
| |
| #include <QtCore/qstring.h> |
| #include <QtCore/qpair.h> |
| |
| #include <numeric> // for std::accumulate |
| #include <functional> // for std::hash |
| |
| #if 0 |
| #pragma qt_class(QHashFunctions) |
| #endif |
| |
| #if defined(Q_CC_MSVC) |
| #pragma warning( push ) |
| #pragma warning( disable : 4311 ) // disable pointer truncation warning |
| #pragma warning( disable : 4127 ) // conditional expression is constant |
| #endif |
| |
| QT_BEGIN_NAMESPACE |
| |
| class QBitArray; |
| class QByteArray; |
| class QString; |
| class QStringRef; |
| class QLatin1String; |
| |
| Q_CORE_EXPORT int qGlobalQHashSeed(); |
| Q_CORE_EXPORT void qSetGlobalQHashSeed(int newSeed); |
| |
| Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qHashBits(const void *p, size_t size, uint seed = 0) noexcept; |
| |
| Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(char key, uint seed = 0) noexcept { return uint(key) ^ seed; } |
| Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(uchar key, uint seed = 0) noexcept { return uint(key) ^ seed; } |
| Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(signed char key, uint seed = 0) noexcept { return uint(key) ^ seed; } |
| Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(ushort key, uint seed = 0) noexcept { return uint(key) ^ seed; } |
| Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(short key, uint seed = 0) noexcept { return uint(key) ^ seed; } |
| Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(uint key, uint seed = 0) noexcept { return key ^ seed; } |
| Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(int key, uint seed = 0) noexcept { return uint(key) ^ seed; } |
| Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(ulong key, uint seed = 0) noexcept |
| { |
| return (sizeof(ulong) > sizeof(uint)) |
| ? (uint(((key >> (8 * sizeof(uint) - 1)) ^ key) & (~0U)) ^ seed) |
| : (uint(key & (~0U)) ^ seed); |
| } |
| Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(long key, uint seed = 0) noexcept { return qHash(ulong(key), seed); } |
| Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(quint64 key, uint seed = 0) noexcept |
| { |
| return uint(((key >> (8 * sizeof(uint) - 1)) ^ key) & (~0U)) ^ seed; |
| } |
| Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(qint64 key, uint seed = 0) noexcept { return qHash(quint64(key), seed); } |
| Q_CORE_EXPORT Q_DECL_CONST_FUNCTION uint qHash(float key, uint seed = 0) noexcept; |
| Q_CORE_EXPORT Q_DECL_CONST_FUNCTION uint qHash(double key, uint seed = 0) noexcept; |
| #if !defined(Q_OS_DARWIN) || defined(Q_CLANG_QDOC) |
| Q_CORE_EXPORT Q_DECL_CONST_FUNCTION uint qHash(long double key, uint seed = 0) noexcept; |
| #endif |
| Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(const QChar key, uint seed = 0) noexcept { return qHash(key.unicode(), seed); } |
| Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qHash(const QByteArray &key, uint seed = 0) noexcept; |
| #if QT_STRINGVIEW_LEVEL < 2 |
| Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qHash(const QString &key, uint seed = 0) noexcept; |
| Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qHash(const QStringRef &key, uint seed = 0) noexcept; |
| #endif |
| Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qHash(QStringView key, uint seed = 0) noexcept; |
| Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qHash(const QBitArray &key, uint seed = 0) noexcept; |
| Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qHash(QLatin1String key, uint seed = 0) noexcept; |
| Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qt_hash(QStringView key, uint chained = 0) noexcept; |
| |
| Q_DECL_CONST_FUNCTION inline uint qHash(std::nullptr_t, uint seed = 0) noexcept |
| { |
| return qHash(reinterpret_cast<quintptr>(nullptr), seed); |
| } |
| |
| template <class T> inline uint qHash(const T *key, uint seed = 0) noexcept |
| { |
| return qHash(reinterpret_cast<quintptr>(key), seed); |
| } |
| template<typename T> inline uint qHash(const T &t, uint seed) |
| noexcept(noexcept(qHash(t))) |
| { return qHash(t) ^ seed; } |
| |
| namespace QtPrivate { |
| |
| struct QHashCombine { |
| typedef uint result_type; |
| template <typename T> |
| Q_DECL_CONSTEXPR result_type operator()(uint seed, const T &t) const noexcept(noexcept(qHash(t))) |
| // combiner taken from N3876 / boost::hash_combine |
| { return seed ^ (qHash(t) + 0x9e3779b9 + (seed << 6) + (seed >> 2)) ; } |
| }; |
| |
| struct QHashCombineCommutative { |
| // QHashCombine is a good hash combiner, but is not commutative, |
| // ie. it depends on the order of the input elements. That is |
| // usually what we want: {0,1,3} should hash differently than |
| // {1,3,0}. Except when it isn't (e.g. for QSet and |
| // QHash). Therefore, provide a commutative combiner, too. |
| typedef uint result_type; |
| template <typename T> |
| Q_DECL_CONSTEXPR result_type operator()(uint seed, const T &t) const noexcept(noexcept(qHash(t))) |
| { return seed + qHash(t); } // don't use xor! |
| }; |
| |
| } // namespace QtPrivate |
| |
| template <typename InputIterator> |
| inline uint qHashRange(InputIterator first, InputIterator last, uint seed = 0) |
| noexcept(noexcept(qHash(*first))) // assume iterator operations don't throw |
| { |
| return std::accumulate(first, last, seed, QtPrivate::QHashCombine()); |
| } |
| |
| template <typename InputIterator> |
| inline uint qHashRangeCommutative(InputIterator first, InputIterator last, uint seed = 0) |
| noexcept(noexcept(qHash(*first))) // assume iterator operations don't throw |
| { |
| return std::accumulate(first, last, seed, QtPrivate::QHashCombineCommutative()); |
| } |
| |
| template <typename T1, typename T2> inline uint qHash(const QPair<T1, T2> &key, uint seed = 0) |
| noexcept(noexcept(qHash(key.first, seed)) && noexcept(qHash(key.second, seed))) |
| { |
| uint h1 = qHash(key.first, seed); |
| uint h2 = qHash(key.second, seed); |
| return ((h1 << 16) | (h1 >> 16)) ^ h2 ^ seed; |
| } |
| |
| template <typename T1, typename T2> inline uint qHash(const std::pair<T1, T2> &key, uint seed = 0) |
| noexcept(noexcept(qHash(key.first, seed)) && noexcept(qHash(key.second, seed))) |
| { |
| QtPrivate::QHashCombine hash; |
| seed = hash(seed, key.first); |
| seed = hash(seed, key.second); |
| return seed; |
| } |
| |
| #define QT_SPECIALIZE_STD_HASH_TO_CALL_QHASH(Class, Arguments) \ |
| QT_BEGIN_INCLUDE_NAMESPACE \ |
| namespace std { \ |
| template <> \ |
| struct hash< QT_PREPEND_NAMESPACE(Class) > { \ |
| using argument_type = QT_PREPEND_NAMESPACE(Class); \ |
| using result_type = size_t; \ |
| size_t operator()(Arguments s) const \ |
| noexcept(noexcept(QT_PREPEND_NAMESPACE(qHash)(s))) \ |
| { \ |
| /* this seeds qHash with the result of */ \ |
| /* std::hash applied to an int, to reap */ \ |
| /* any protection against predictable hash */ \ |
| /* values the std implementation may provide */ \ |
| return QT_PREPEND_NAMESPACE(qHash)(s, \ |
| QT_PREPEND_NAMESPACE(qHash)( \ |
| std::hash<int>{}(0))); \ |
| } \ |
| }; \ |
| } \ |
| QT_END_INCLUDE_NAMESPACE \ |
| /*end*/ |
| |
| #define QT_SPECIALIZE_STD_HASH_TO_CALL_QHASH_BY_CREF(Class) \ |
| QT_SPECIALIZE_STD_HASH_TO_CALL_QHASH(Class, const argument_type &) |
| #define QT_SPECIALIZE_STD_HASH_TO_CALL_QHASH_BY_VALUE(Class) \ |
| QT_SPECIALIZE_STD_HASH_TO_CALL_QHASH(Class, argument_type) |
| |
| QT_SPECIALIZE_STD_HASH_TO_CALL_QHASH_BY_CREF(QString) |
| QT_SPECIALIZE_STD_HASH_TO_CALL_QHASH_BY_CREF(QStringRef) |
| QT_SPECIALIZE_STD_HASH_TO_CALL_QHASH_BY_VALUE(QStringView) |
| QT_SPECIALIZE_STD_HASH_TO_CALL_QHASH_BY_VALUE(QLatin1String) |
| QT_SPECIALIZE_STD_HASH_TO_CALL_QHASH_BY_CREF(QByteArray) |
| QT_SPECIALIZE_STD_HASH_TO_CALL_QHASH_BY_CREF(QBitArray) |
| |
| QT_END_NAMESPACE |
| |
| #if defined(Q_CC_MSVC) |
| #pragma warning( pop ) |
| #endif |
| |
| #endif // QHASHFUNCTIONS_H |