| 1 | // Copyright (C) 2023 Ahmad Samir <a.samirh78@gmail.com> |
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| 2 | // Copyright (C) 2023 The Qt Company Ltd. |
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| 3 | // 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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| 4 | |
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| 5 | #ifndef Q20MAP_H |
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| 6 | #define Q20MAP_H |
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| 7 | |
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| 8 | #include <QtCore/qtconfigmacros.h> |
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| 9 | |
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| 10 | #include <map> |
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| 11 | #if __has_include(<memory_resource>) |
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| 12 | # include <memory_resource> |
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| 13 | #endif |
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| 14 | |
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| 15 | // |
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| 16 | // W A R N I N G |
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| 17 | // ------------- |
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| 18 | // |
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| 19 | // This file is not part of the Qt API. Types and functions defined in this |
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| 20 | // file can reliably be replaced by their std counterparts, once available. |
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| 21 | // You may use these definitions in your own code, but be aware that we |
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| 22 | // will remove them once Qt depends on the C++ version that supports |
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| 23 | // them in namespace std. There will be NO deprecation warning, the |
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| 24 | // definitions will JUST go away. |
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| 25 | // |
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| 26 | // If you can't agree to these terms, don't use these definitions! |
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| 27 | // |
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| 28 | // We mean it. |
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| 29 | // |
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| 30 | |
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| 31 | QT_BEGIN_NAMESPACE |
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| 32 | |
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| 33 | namespace q20 { |
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| 34 | // like std::erase/std::erase_if for std::map |
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| 35 | #if defined(__cpp_lib_erase_if) && __cpp_lib_erase_if >= 202002L // the one returning size_type |
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| 36 | using std::erase_if; |
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| 37 | #else |
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| 38 | |
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| 39 | // Make it more specialized than the compiler's, so that our implementation is preferred over |
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| 40 | // the compiler's (which may be present, but return void instead of the number of erased elements). |
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| 41 | |
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| 42 | #define MAKE_OVERLOAD(map, allocator) \ |
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| 43 | template <typename Key, typename T, typename Compare, typename Pred> \ |
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| 44 | constexpr typename std::map<Key, T, Compare, std::allocator<std::pair<const Key, T>>>::size_type \ |
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| 45 | erase_if(std::map<Key, T, Compare, std::allocator<std::pair<const Key, T>>> &c, Pred p) \ |
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| 46 | { \ |
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| 47 | const auto origSize = c.size(); \ |
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| 48 | for (auto it = c.begin(), end = c.end(); it != end; /* erasing */) { \ |
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| 49 | if (p(*it)) \ |
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| 50 | it = c.erase(it); \ |
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| 51 | else \ |
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| 52 | ++it; \ |
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| 53 | } \ |
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| 54 | return origSize - c.size(); \ |
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| 55 | } \ |
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| 56 | /* end */ |
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| 57 | |
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| 58 | MAKE_OVERLOAD(map, allocator) |
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| 59 | MAKE_OVERLOAD(multimap, allocator) |
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| 60 | #ifdef __cpp_lib_polymorphic_allocator |
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| 61 | MAKE_OVERLOAD(map, pmr::polymorphic_allocator) |
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| 62 | MAKE_OVERLOAD(multimap, pmr::polymorphic_allocator) |
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| 63 | #endif // __cpp_lib_polymorphic_allocator |
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| 64 | |
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| 65 | #undef MAKE_OVERLOAD |
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| 66 | |
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| 67 | #endif // __cpp_lib_erase_if |
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| 68 | } // namespace q20 |
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| 69 | |
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| 70 | QT_END_NAMESPACE |
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| 71 | |
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| 72 | #endif /* Q20MAP_H */ |
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| 73 | |
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