现在我想实现在一个容器中存放固定数量的数据而且要按下标顺序存放，存放的是自定义对象，怎么实现？跪求
qt
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下面是Qt的容器
As special cases, the QCache and QContiguousCache classes provide efficient hash-lookup of objects in a limited cache storage.
Class Summary
QList<T> This is by far the most commonly used container class. It stores a list of values of a given type (T) that can be accessed by index. Internally, the QList is implemented using an array, ensuring that index-based access is very fast.
Items can be added at either end of the list using QList::append() and QList::prepend(), or they can be inserted in the middle using QList::insert(). More than any other container class, QList is highly optimized to expand to as little code as possible in the executable. QStringList inherits from QList<QString>.
QLinkedList<T> This is similar to QList, except that it uses iterators rather than integer indexes to access items. It also provides better performance than QList when inserting in the middle of a huge list, and it has nicer iterator semantics. (Iterators pointing to an item in a QLinkedList remain valid as long as the item exists, whereas iterators to a QList can become invalid after any insertion or removal.)
QVector<T> This stores an array of values of a given type at adjacent positions in memory. Inserting at the front or in the middle of a vector can be quite slow, because it can lead to large numbers of items having to be moved by one position in memory.
QStack<T> This is a convenience subclass of QVector that provides "last in, first out" (LIFO) semantics. It adds the following functions to those already present in QVector: push(), pop(), and top().
QQueue<T> This is a convenience subclass of QList that provides "first in, first out" (FIFO) semantics. It adds the following functions to those already present in QList: enqueue(), dequeue(), and head().
QSet<T> This provides a single-valued mathematical set with fast lookups.
QMap<Key, T> This provides a dictionary (associative array) that maps keys of type Key to values of type T. Normally each key is associated with a single value. QMap stores its data in Key order; if order doesn't matter QHash is a faster alternative.