qsequentialiterable.h

Go to the documentation of this file.

// Copyright (C) 2020 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 QSEQUENTIALITERABLE_H
#define QSEQUENTIALITERABLE_H
 
#include <QtCore/qiterable.h>
#include <QtCore/qvariant.h>
 
QT_BEGIN_NAMESPACE
 
class Q_CORE_EXPORT QSequentialIterator : public QIterator<QMetaSequence>
{
public:
    using value_type = QVariant;
    using reference = QVariantRef<QSequentialIterator>;
    using pointer = QVariantPointer<QSequentialIterator>;
 
    QSequentialIterator(QIterator &&it)
        : QIterator(std::move(it))
    {}
 
    QVariantRef<QSequentialIterator> operator*() const;
    QVariantPointer<QSequentialIterator> operator->() const;
};
 
class Q_CORE_EXPORT QSequentialConstIterator : public QConstIterator<QMetaSequence>
{
public:
    using value_type = QVariant;
    using reference = const QVariant &;
    using pointer = QVariantConstPointer;
 
    QSequentialConstIterator(QConstIterator &&it)
        : QConstIterator(std::move(it))
    {}
 
    QVariant operator*() const;
    QVariantConstPointer operator->() const;
};
 
class Q_CORE_EXPORT QSequentialIterable : public QIterable<QMetaSequence>
{
public:
    using iterator = QTaggedIterator<QSequentialIterator, void>;
    using const_iterator = QTaggedIterator<QSequentialConstIterator, void>;
 
    using RandomAccessIterator = QTaggedIterator<iterator, std::random_access_iterator_tag>;
    using BidirectionalIterator = QTaggedIterator<iterator, std::bidirectional_iterator_tag>;
    using ForwardIterator = QTaggedIterator<iterator, std::forward_iterator_tag>;
    using InputIterator = QTaggedIterator<iterator, std::input_iterator_tag>;
 
    using RandomAccessConstIterator = QTaggedIterator<const_iterator, std::random_access_iterator_tag>;
    using BidirectionalConstIterator = QTaggedIterator<const_iterator, std::bidirectional_iterator_tag>;
    using ForwardConstIterator = QTaggedIterator<const_iterator, std::forward_iterator_tag>;
    using InputConstIterator = QTaggedIterator<const_iterator, std::input_iterator_tag>;
 
    template<class T>
    QSequentialIterable(const T *p)
        : QIterable(QMetaSequence::fromContainer<T>(), p)
    {
        Q_UNUSED(m_revision);
    }
 
    template<class T>
    QSequentialIterable(T *p)
        : QIterable(QMetaSequence::fromContainer<T>(), p)
    {
    }
 
    QSequentialIterable()
        : QIterable(QMetaSequence(), nullptr)
    {
    }
 
    template<typename Pointer>
    QSequentialIterable(const QMetaSequence &metaSequence, Pointer iterable)
        : QIterable(metaSequence, iterable)
    {
    }
 
    // ### Qt7: Pass QMetaType as value rather than const ref.
    QSequentialIterable(const QMetaSequence &metaSequence, const QMetaType &metaType,
                        void *iterable)
        : QIterable(metaSequence, metaType.alignOf(), iterable)
    {
    }
 
    // ### Qt7: Pass QMetaType as value rather than const ref.
    QSequentialIterable(const QMetaSequence &metaSequence, const QMetaType &metaType,
                        const void *iterable)
        : QIterable(metaSequence, metaType.alignOf(), iterable)
    {
    }
 
    QSequentialIterable(QIterable<QMetaSequence> &&other) : QIterable(std::move(other)) {}
 
    QSequentialIterable &operator=(QIterable<QMetaSequence> &&other)
    {
        QIterable::operator=(std::move(other));
        return *this;
    }
 
    const_iterator begin() const { return constBegin(); }
    const_iterator end() const { return constEnd(); }
 
    const_iterator constBegin() const { return const_iterator(QIterable::constBegin()); }
    const_iterator constEnd() const { return const_iterator(QIterable::constEnd()); }
 
    iterator mutableBegin() { return iterator(QIterable::mutableBegin()); }
    iterator mutableEnd() { return iterator(QIterable::mutableEnd()); }
 
    QVariant at(qsizetype idx) const;
    void set(qsizetype idx, const QVariant &value);
 
    enum Position { Unspecified, AtBegin, AtEnd };
    void addValue(const QVariant &value, Position position = Unspecified);
    void removeValue(Position position = Unspecified);
 
    QMetaType valueMetaType() const;
};
 
template<>
inline QVariantRef<QSequentialIterator>::operator QVariant() const
{
    if (m_pointer == nullptr)
        return QVariant();
    const QMetaType metaType(m_pointer->metaContainer().valueMetaType());
    QVariant v(metaType);
    void *dataPtr = metaType == QMetaType::fromType<QVariant>() ? &v : v.data();
    m_pointer->metaContainer().valueAtIterator(m_pointer->constIterator(), dataPtr);
    return v;
}
 
template<>
inline QVariantRef<QSequentialIterator> &QVariantRef<QSequentialIterator>::operator=(
        const QVariant &value)
{
    if (m_pointer == nullptr)
        return *this;
 
    QtPrivate::QVariantTypeCoercer coercer;
    m_pointer->metaContainer().setValueAtIterator(
                m_pointer->constIterator(),
                coercer.coerce(value, m_pointer->metaContainer().valueMetaType()));
    return *this;
}
 
Q_DECLARE_TYPEINFO(QSequentialIterable, Q_RELOCATABLE_TYPE);
Q_DECLARE_TYPEINFO(QSequentialIterable::iterator, Q_RELOCATABLE_TYPE);
Q_DECLARE_TYPEINFO(QSequentialIterable::const_iterator, Q_RELOCATABLE_TYPE);
 
QT_END_NAMESPACE
 
#endif // QSEQUENTIALITERABLE_H