qlinkedlist.cpp

奇趣公司比较新的qt/emd版本

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#include "qlinkedlist.h"

QLinkedListData QLinkedListData::shared_null = {
    &QLinkedListData::shared_null, &QLinkedListData::shared_null, Q_ATOMIC_INIT(1), 0, true
};

/*! \class QLinkedList
    \brief The QLinkedList class is a template class that provides linked lists.

    \ingroup tools
    \ingroup shared
    \mainclass
    \reentrant

    QLinkedList\<T\> is one of Qt's generic \l{container classes}. It
    stores a list of values and provides iterator-based access as
    well as \l{constant time} insertions and removals.

    QList\<T\>, QLinkedList\<T\>, and QVector\<T\> provide similar
    functionality. Here's an overview:

    \list
    \i For most purposes, QList is the right class to use. Its
       index-based API is more convenient than QLinkedList's
       iterator-based API, and it is usually faster than
       QVector because of the way it stores its items in
       memory (see \l{Algorithmic Complexity} for details).
       It also expands to less code in your executable.
    \i If you need a real linked list, with guarantees of \l{constant
       time} insertions in the middle of the list and iterators to
       items rather than indexes, use QLinkedList.
    \i If you want the items to occupy adjacent memory positions,
       use QVector.
    \endlist

    Here's an example of a QLinkedList that stores integers and a
    QLinkedList that stores QTime values:

    \code
        QLinkedList<int> integerList;
        QLinkedList<QTime> timeList;
    \endcode

    QLinkedList stores a list of items. The default constructor
    creates an empty list. To insert items into the list, you can use
    operator<<():

    \code
        QLinkedList<QString> list;
        list << "one" << "two" << "three";
        // list: ["one", "two", "three"]
    \endcode

    If you want to get the first or last item in a linked list, use
    first() or last(). If you want to remove an item from either end
    of the list, use removeFirst() or removeLast(). If you want to
    remove all occurrences of a given value in the list, use
    removeAll().

    A common requirement is to remove the first or last item in the
    list and do something with it. For this, QLinkedList provides
    takeFirst() and takeLast(). Here's a loop that removes the items
    from a list one at a time and calls \c delete on them:
    \code
        QLinkedList<QWidget *> list;
        ...
        while (!list.isEmpty())
            delete list.takeFirst();
    \endcode

    QLinkedList's value type must be an \l{assignable data type}.
    This covers most data types that are commonly used, but the
    compiler won't let you, for example, store a QWidget as a value;
    instead, store a QWidget *. A few functions have additional
    requirements; for example, contains() and removeAll() expect the
    value type to support \c operator==(). These requirements are
    documented on a per-function basis.

    If you want to insert, modify, or remove items in the middle of
    the list, you must use an iterator. QLinkedList provides both
    \l{Java-style iterators} (QLinkedListIterator and
    QMutableLinkedListIterator) and \l{STL-style iterators}
    (QLinkedList::const_iterator and QLinkedList::iterator). See the
    documentation for these classes for details.

    \sa QListIterator, QMutableListIterator, QList, QVector
*/

/*! \fn QLinkedList::QLinkedList()

    Constructs an empty list.
*/

/*! \fn QLinkedList::QLinkedList(const QLinkedList<T> &other)

    Constructs a copy of \a other.

    This operation occurs in \l{constant time}, because QLinkedList
    is \l{implicitly shared}. This makes returning a QLinkedList from
    a function very fast. If a shared instance is modified, it will
    be copied (copy-on-write), and this takes \l{linear time}.

    \sa operator=()
*/

/*! \fn QLinkedList::~QLinkedList()

    Destroys the list. References to the values in the list, and all
    iterators over this list, become invalid.
*/

/*! \fn QLinkedList<T> &QLinkedList::operator=(const QLinkedList<T> &other)

    Assigns \a other to this list and returns a reference to this
    list.
*/

/*! \fn bool QLinkedList::operator==(const QLinkedList<T> &other) const

    Returns true if \a other is equal to this list; otherwise returns
    false.

    Two lists are considered equal if they contain the same values in
    the same order.

    This function requires the value type to implement \c
    operator==().

    \sa operator!=()
*/

/*! \fn bool QLinkedList::operator!=(const QLinkedList<T> &other) const

    Returns true if \a other is not equal to this list; otherwise
    returns false.

    Two lists are considered equal if they contain the same values in
    the same order.

    This function requires the value type to implement \c
    operator==().

    \sa operator==()
*/

/*! \fn int QLinkedList::size() const

    Returns the number of items in the list.

    \sa isEmpty(), count()
*/

/*! \fn void QLinkedList::detach()

    \internal
*/

/*! \fn bool QLinkedList::isDetached() const

    \internal
*/

/*! \fn void QLinkedList::setSharable(bool sharable)

    \internal
*/

/*! \fn bool QLinkedList::isEmpty() const

    Returns true if the list contains no items; otherwise returns
    false.

    \sa size()
*/

/*! \fn void QLinkedList::clear()

    Removes all the items in the list.

    \sa removeAll()
*/

/*! \fn void QLinkedList::append(const T &value)

    Inserts \a value at the end of the list.

    Example:
    \code
        QLinkedList<QString> list;
        list.append("one");
        list.append("two");
        list.append("three");
        // list: ["one", "two", "three"]
    \endcode

    This is the same as list.insert(end(), \a value).

    \sa operator<<(), prepend(), insert()
*/

/*! \fn void QLinkedList::prepend(const T &value)

    Inserts \a value at the beginning of the list.

    Example:
    \code
        QLinkedList<QString> list;
        list.prepend("one");
        list.prepend("two");
        list.prepend("three");
        // list: ["three", "two", "one"]
    \endcode

    This is the same as list.insert(begin(), \a value).

    \sa append(), insert()
*/

/*! \fn int QLinkedList::removeAll(const T &value)

    Removes all occurrences of \a value in the list.

    Example:
    \code
        QList<QString> list;
        list << "sun" << "cloud" << "sun" << "rain";
        list.removeAll("sun");
        // list: ["cloud", "rain"]
    \endcode

    This function requires the value type to have an implementation of
    \c operator==().

    \sa insert()
*/

/*! \fn bool QLinkedList::contains(const T &value) const

    Returns true if the list contains an occurrence of \a value;
    otherwise returns false.

    This function requires the value type to have an implementation of
    \c operator==().

    \sa QListIterator::findNext(), QListIterator::findPrevious()
*/

/*! \fn int QLinkedList::count(const T &value) const

    Returns the number of occurrences of \a value in the list.

    This function requires the value type to have an implementation of
    \c operator==().

    \sa contains()
*/

/*! \fn QLinkedList::iterator QLinkedList::begin()

    Returns an \l{STL-style iterator} pointing to the first item in
    the list.

    \sa constBegin(), end()
*/

/*! \fn QLinkedList::const_iterator QLinkedList::begin() const

    \overload
*/

/*! \fn QLinkedList::const_iterator QLinkedList::constBegin() const

    Returns a const \l{STL-style iterator} pointing to the first item
    in the list.

    \sa begin(), constEnd()
*/

/*! \fn QLinkedList::iterator QLinkedList::end()

    Returns an \l{STL-style iterator} pointing to the imaginary item
    after the last item in the list.

    \sa begin(), constEnd()
*/

/*! \fn QLinkedList::const_iterator QLinkedList::end() const

    \overload
*/

/*! \fn QLinkedList::const_iterator QLinkedList::constEnd() const

    Returns a const \l{STL-style iterator} pointing to the imaginary
    item after the last item in the list.

    \sa constBegin(), end()
*/

/*! \fn QLinkedList::iterator QLinkedList::insert(iterator before, const T &value)

    Inserts \a value in front of the item pointed to by the iterator
    \a before. Returns an iterator pointing at the inserted item.

    \sa erase()
*/

/*! \fn QLinkedList::iterator QLinkedList::erase(iterator pos)

    Removes the item pointed to by the iterator \a pos from the list,
    and returns an iterator to the next item in the list (which may be
    end()).

    \sa insert()
*/

/*! \fn QLinkedList::iterator QLinkedList::erase(iterator begin, iterator end)

    \overload

    Removes all the items from \a begin up to (but not including) \a
    end.
*/

/*! \typedef QLinkedList::Iterator

    Qt-style synonym for QList::iterator.
*/

/*! \typedef QLinkedList::ConstIterator

    Qt-style synonym for QList::const_iterator.
*/

/*!
    \typedef QLinkedList::size_type

    Typedef for int. Provided for STL compatibility.
*/

/*!
    \typedef QLinkedList::value_type

    Typedef for T. Provided for STL compatibility.
*/

/*!
    \typedef QLinkedList::pointer

    Typedef for T *. Provided for STL compatibility.
*/

/*!
    \typedef QLinkedList::const_pointer

    Typedef for const T *. Provided for STL compatibility.
*/

/*!
    \typedef QLinkedList::reference

    Typedef for T &. Provided for STL compatibility.
*/

/*!
    \typedef QLinkedList::const_reference

    Typedef for const T &. Provided for STL compatibility.
*/

/*!