123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125 | // Copyright (C) 2016 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 QPOINTER_H#define QPOINTER_H#include <QtCore/qcompare.h>#include <QtCore/qsharedpointer.h>#include <QtCore/qtypeinfo.h>#ifndef QT_NO_QOBJECT QT_BEGIN_NAMESPACE class QVariant;template<class T>class QPointer {static_assert(!std::is_pointer<T>::value,"QPointer's template type must not be a pointer type");template<typename X>using if_convertible =std::enable_if_t<std::is_convertible_v<X*, T*>,bool>;template<typename X>friend class QPointer;using QObjectType = typename std::conditional<std::is_const<T>::value,const QObject, QObject>::type; QWeakPointer<QObjectType> wp;public: Q_NODISCARD_CTOR QPointer() noexcept =default; Q_NODISCARD_CTOR constexprQPointer(std::nullptr_t) noexcept : QPointer{} {} Q_WEAK_OVERLOAD Q_NODISCARD_CTOR inlineQPointer(T *p) :wp(p,true) { }// compiler-generated copy/move ctor/assignment operators are fine!// compiler-generated dtor is fine!template<typename X, if_convertible<X> =true> Q_NODISCARD_CTOR QPointer(QPointer<X> &&other) noexcept :wp(std::exchange(other.wp,nullptr).internalData(),true) {}template<typename X, if_convertible<X> =true> Q_NODISCARD_CTOR QPointer(const QPointer<X> &other) noexcept :wp(other.wp.internalData(),true) {}template<typename X, if_convertible<X> =true> QPointer &operator=(const QPointer<X> &other) noexcept {QPointer(other).swap(*this);return*this;}template<typename X, if_convertible<X> =true> QPointer &operator=(QPointer<X> &&other) noexcept {QPointer(std::move(other)).swap(*this);return*this;}#ifdef Q_QDOC// Stop qdoc from complaining about missing function~QPointer();#endifinlinevoidswap(QPointer &other) noexcept { wp.swap(other.wp); }inline QPointer<T> &operator=(T* p){ wp.assign(static_cast<QObjectType*>(p));return*this; } T*data()const noexcept {return static_cast<T*>(wp.internalData()); } T*get()const noexcept {returndata(); } T*operator->()const noexcept {returndata(); } T&operator*()const noexcept {return*data(); }operator T*()const noexcept {returndata(); }boolisNull()const noexcept {return wp.isNull(); }explicit operatorbool()const noexcept {return!isNull(); }voidclear() noexcept { wp.clear(); }friendvoidswap(QPointer &lhs, QPointer &rhs) noexcept { lhs.swap(rhs); }private:template<typename X>friendboolcomparesEqual(const QPointer &lhs,const QPointer<X> &rhs) noexcept {return lhs.data() == rhs.data(); }QT_DECLARE_EQUALITY_OPERATORS_HELPER(QPointer, QPointer<X>,/* non-constexpr */,noexcept(true),template<typename X>)template<typename X>friendboolcomparesEqual(const QPointer &lhs, X *rhs) noexcept {return lhs.data() == rhs; }Q_DECLARE_EQUALITY_COMPARABLE(QPointer, X*,template<typename X>)friendboolcomparesEqual(const QPointer &lhs,std::nullptr_t) noexcept {return lhs.isNull(); }Q_DECLARE_EQUALITY_COMPARABLE(QPointer,std::nullptr_t)};template<class T>Q_DECLARE_TYPEINFO_BODY(QPointer<T>, Q_RELOCATABLE_TYPE);template<typename T> QPointer<T>qPointerFromVariant(const QVariant &variant){constauto wp =QtSharedPointer::weakPointerFromVariant_internal(variant);return QPointer<T>{qobject_cast<T*>(QtPrivate::EnableInternalData::internalData(wp))};} QT_END_NAMESPACE #endif// QT_NO_QOBJECT#endif// QPOINTER_H
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