| 1 | // Copyright (C) 2022 The Qt Company Ltd. |
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| 2 | // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only |
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| 3 | |
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| 4 | #ifndef QSWAP_H |
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| 5 | #define QSWAP_H |
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| 6 | |
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| 7 | #include <QtCore/qtconfigmacros.h> |
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| 8 | #include <QtCore/qcompilerdetection.h> |
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| 9 | |
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| 10 | #if 0 |
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| 11 | #pragma qt_class(QtSwap) |
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| 12 | #pragma qt_sync_stop_processing |
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| 13 | #endif |
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| 14 | |
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| 15 | QT_BEGIN_NAMESPACE |
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| 16 | |
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| 17 | QT_WARNING_PUSH |
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| 18 | // warning: noexcept-expression evaluates to 'false' because of a call to 'void swap(..., ...)' |
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| 19 | QT_WARNING_DISABLE_GCC("-Wnoexcept" ) |
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| 20 | |
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| 21 | namespace QtPrivate |
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| 22 | { |
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| 23 | namespace SwapExceptionTester { // insulate users from the "using std::swap" below |
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| 24 | using std::swap; // import std::swap |
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| 25 | template <typename T> |
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| 26 | void checkSwap(T &t) |
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| 27 | noexcept(noexcept(swap(t, t))); |
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| 28 | // declared, but not implemented (only to be used in unevaluated contexts (noexcept operator)) |
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| 29 | } |
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| 30 | } // namespace QtPrivate |
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| 31 | |
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| 32 | // Documented in ../tools/qalgorithm.qdoc |
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| 33 | template <typename T> |
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| 34 | constexpr void qSwap(T &value1, T &value2) |
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| 35 | noexcept(noexcept(QtPrivate::SwapExceptionTester::checkSwap(value1))) |
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| 36 | { |
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| 37 | using std::swap; |
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| 38 | swap(value1, value2); |
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| 39 | } |
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| 40 | |
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| 41 | // pure compile-time micro-optimization for our own headers, so not documented: |
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| 42 | template <typename T> |
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| 43 | constexpr inline void qt_ptr_swap(T* &lhs, T* &rhs) noexcept |
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| 44 | { |
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| 45 | T *tmp = lhs; |
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| 46 | lhs = rhs; |
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| 47 | rhs = tmp; |
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| 48 | } |
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| 49 | |
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| 50 | QT_WARNING_POP |
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| 51 | |
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| 52 | QT_END_NAMESPACE |
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| 53 | |
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| 54 | #endif // QSWAP_H |
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| 55 | |
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