// Copyright (C) 2022 The Qt Company Ltd. // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only #ifndef QTCLASSHELPERMACROS_H #define QTCLASSHELPERMACROS_H #include #if 0 #pragma qt_class(QtClassHelperMacros) #pragma qt_sync_stop_processing #endif QT_BEGIN_NAMESPACE #if defined(__cplusplus) /* Some classes do not permit copies to be made of an object. These classes contains a private copy constructor and assignment operator to disable copying (the compiler gives an error message). */ #define Q_DISABLE_COPY(Class) \ Class(const Class &) = delete;\ Class &operator=(const Class &) = delete; #define Q_DISABLE_COPY_MOVE(Class) \ Q_DISABLE_COPY(Class) \ Class(Class &&) = delete; \ Class &operator=(Class &&) = delete; /* Implementing a move assignment operator using an established technique (move-and-swap, pure swap) is just boilerplate. Here's a couple of *private* macros for convenience. To know which one to use: * if you don't have a move constructor (*) => use pure swap; * if you have a move constructor, then * if your class holds just memory (no file handles, no user-defined datatypes, etc.) => use pure swap; * use move and swap. The preference should always go for the move-and-swap one, as it will deterministically destroy the data previously held in *this, and not "dump" it in the moved-from object (which may then be alive for longer). The requirement for either macro is the presence of a member swap(), which any value class that defines its own special member functions should have anyhow. (*) Many value classes in Qt do not have move constructors; mostly, the implicitly shared classes using QSharedDataPointer and friends. The reason is mostly historical: those classes require either an out-of-line move constructor, which we could not provide before we made C++11 mandatory (and that we don't like anyhow), or an out-of-line dtor for the Q(E)DSP member (cf. QPixmap). If you can however add a move constructor to a class lacking it, consider doing so, then reevaluate which macro to choose. */ #define QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_MOVE_AND_SWAP(Class) \ Class &operator=(Class &&other) noexcept { \ Class moved(std::move(other)); \ swap(moved); \ return *this; \ } #define QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_PURE_SWAP(Class) \ Class &operator=(Class &&other) noexcept { \ swap(other); \ return *this; \ } template inline T *qGetPtrHelper(T *ptr) noexcept { return ptr; } template inline auto qGetPtrHelper(Ptr &ptr) noexcept -> decltype(ptr.get()) { static_assert(noexcept(ptr.get()), "Smart d pointers for Q_DECLARE_PRIVATE must have noexcept get()"); return ptr.get(); } class QObject; class QObjectPrivate; namespace QtPrivate { template void assertObjectType(QObjectPrivate *d); inline const QObject *getQObject(const QObjectPrivate *d); } #define Q_DECLARE_PRIVATE(Class) \ inline Class##Private* d_func() noexcept \ { Q_CAST_IGNORE_ALIGN(return reinterpret_cast(qGetPtrHelper(d_ptr));) } \ inline const Class##Private* d_func() const noexcept \ { Q_CAST_IGNORE_ALIGN(return reinterpret_cast(qGetPtrHelper(d_ptr));) } \ friend class Class##Private; #define Q_DECLARE_PRIVATE_D(Dptr, Class) \ inline Class##Private* d_func() noexcept \ { Q_CAST_IGNORE_ALIGN(return reinterpret_cast(qGetPtrHelper(Dptr));) } \ inline const Class##Private* d_func() const noexcept \ { Q_CAST_IGNORE_ALIGN(return reinterpret_cast(qGetPtrHelper(Dptr));) } \ friend class Class##Private; #define Q_DECLARE_PUBLIC(Class) \ inline Class* q_func() noexcept { return static_cast(q_ptr); } \ inline const Class* q_func() const noexcept { return static_cast(q_ptr); } \ friend class Class; \ friend const QObject *QtPrivate::getQObject(const QObjectPrivate *d); \ template friend void QtPrivate::assertObjectType(QObjectPrivate *d); #define Q_D(Class) Class##Private * const d = d_func() #define Q_Q(Class) Class * const q = q_func() /* Specialize a shared type with: Q_DECLARE_SHARED(type) where 'type' is the name of the type to specialize. NOTE: shared types must define a member-swap, and be defined in the same namespace as Qt for this to work. */ #define Q_DECLARE_SHARED(TYPE) \ Q_DECLARE_TYPEINFO(TYPE, Q_RELOCATABLE_TYPE); \ inline void swap(TYPE &value1, TYPE &value2) \ noexcept(noexcept(value1.swap(value2))) \ { value1.swap(value2); } #endif // __cplusplus QT_END_NAMESPACE #endif // QTCLASSHELPERMACROS_H