| 1 | // Copyright (C) 2024 The Qt Company Ltd. |
|---|---|
| 2 | // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only |
| 3 | |
| 4 | #ifndef Q20UTILITY_H |
| 5 | #define Q20UTILITY_H |
| 6 | |
| 7 | #include <QtCore/qtconfigmacros.h> |
| 8 | |
| 9 | #include <utility> |
| 10 | |
| 11 | // |
| 12 | // W A R N I N G |
| 13 | // ------------- |
| 14 | // |
| 15 | // This file is not part of the Qt API. Types and functions defined in this |
| 16 | // file can reliably be replaced by their std counterparts, once available. |
| 17 | // You may use these definitions in your own code, but be aware that we |
| 18 | // will remove them once Qt depends on the C++ version that supports |
| 19 | // them in namespace std. There will be NO deprecation warning, the |
| 20 | // definitions will JUST go away. |
| 21 | // |
| 22 | // If you can't agree to these terms, don't use these definitions! |
| 23 | // |
| 24 | // We mean it. |
| 25 | // |
| 26 | |
| 27 | QT_BEGIN_NAMESPACE |
| 28 | |
| 29 | // like C++20 std::exchange (ie. constexpr, not yet noexcept) |
| 30 | namespace q20 { |
| 31 | #ifdef __cpp_lib_constexpr_algorithms |
| 32 | using std::exchange; |
| 33 | #else |
| 34 | template <typename T, typename U = T> |
| 35 | constexpr T exchange(T& obj, U&& newValue) |
| 36 | { |
| 37 | T old = std::move(obj); |
| 38 | obj = std::forward<U>(newValue); |
| 39 | return old; |
| 40 | } |
| 41 | #endif |
| 42 | } |
| 43 | |
| 44 | QT_END_NAMESPACE |
| 45 | |
| 46 | #endif /* Q20UTILITY_H */ |
| 47 |
Definitions
Learn Advanced QML with KDAB
Find out more