/******************************************************************************** Copyright (C) 1992-2006 Trolltech ASA. All rights reserved.**** This file is part of the QtCore module of the Qt Toolkit.**** This file may be used under the terms of the GNU General Public** License version 2.0 as published by the Free Software Foundation** and appearing in the file LICENSE.GPL included in the packaging of** this file.  Please review the following information to ensure GNU** General Public Licensing requirements will be met:** http://www.trolltech.com/products/qt/opensource.html**** If you are unsure which license is appropriate for your use, please** review the following information:** http://www.trolltech.com/products/qt/licensing.html or contact the** sales department at sales@trolltech.com.**** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.******************************************************************************/#include "qvector.h"#include "qtools_p.h"#include <string.h>QVectorData QVectorData::shared_null = { Q_ATOMIC_INIT(1), 0, 0, true };QVectorData* QVectorData::malloc(int sizeofTypedData, int size, int sizeofT, QVectorData* init){    QVectorData* p = (QVectorData *)qMalloc(sizeofTypedData + (size - 1) * sizeofT);    ::memcpy(p, init, sizeofTypedData + (qMin(size, init->alloc) - 1) * sizeofT);    return p;}int QVectorData::grow(int sizeofTypedData, int size, int sizeofT, bool excessive){    if (excessive)        return size + size / 2;    return qAllocMore(size * sizeofT, sizeofTypedData - sizeofT) / sizeofT;}/*!     \class QVector    \brief The QVector class is a template class that provides a dynamic array.    \ingroup tools    \ingroup shared    \mainclass    \reentrant    QVector\<T\> is one of Qt's generic \l{container classes}. It    stores its items in adjacent memory locations and provides fast    index-based access.    QList\<T\>, QLinkedList\<T\>, and QVarLengthArray\<T\> provide    similar functionality. Here's an overview:    \list    \i For most purposes, QList is the right class to use. Operations       like prepend() and insert() are usually faster than with       QVector because of the way QList stores its items in memory       (see \l{Algorithmic Complexity} for details),       and its index-based API is more convenient than QLinkedList's       iterator-based API. 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.    \i If you want a low-level variable-size array, QVarLengthArray    may be sufficient.    \endlist    Here's an example of a QVector that stores integers and a QVector    that stores QString values:    \code        QVector<int> integerVector;        QVector<QString> stringVector;    \endcode    QVector stores a vector (or array) of items. Typically, vectors    are created with an initial size. For example, the following code    constructs a QVector with 200 elements:    \code        QVector<QString> vector(200);    \endcode    The elements are automatically initialized with a    \l{default-constructed value}. If you want to initialize the    vector with a different value, pass that value as the second    argument to the constructor:    \code        QVector<QString> vector(200, "Pass");    \endcode    You can also call fill() at any time to fill the vector with a    value.    QVector uses 0-based indexes, just like C++ arrays. To access the    item at a particular index position, you can use operator[](). On    non-const vectors, operator[]() returns a reference to the item    that can be used on the left side of an assignment:    \code        if (vector[0] == "Liz")            vector[0] = "Elizabeth";    \endcode    For read-only access, an alternative syntax is to use at():    \code        for (int i = 0; i < vector.size(); ++i) {            if (vector.at(i) == "Alfonso")                cout << "Found Alfonso at position " << i << endl;        }    \endcode    at() can be faster than operator[](), because it never causes a    \l{deep copy} to occur.    Another way to access the data stored in a QVector is to call    data(). The function returns a pointer to the first item in the    vector. You can use the pointer to directly access and modify the    elements stored in the vector. The pointer is also useful if you    need to pass a QVector to a function that accepts a plain C++    array.    If you want to find all occurrences of a particular value in a    vector, use indexOf() or lastIndexOf(). The former searches    forward starting from a given index position, the latter searches    backward. Both return the index of the matching item if they found    one; otherwise, they return -1. For example:    \code        int i = vector.indexOf("Harumi");        if (i != -1)            cout << "First occurrence of Harumi is at position " << i << endl;    \endcode    If you simply want to check whether a vector contains a    particular value, use contains(). If you want to find out how    many times a particular value occurs in the vector, use count().    QVector provides these basic functions to add, move, and remove    items: insert(), replace(), remove(), prepend(), append(). With    the exception of append(), these functions can be slow (\l{linear    time}) for large vectors, because they require moving many items    in the vector by one position in memory. If you want a container    class that provides fast insertion/removal in the middle, use    QList or QLinkedList instead.    Unlike plain C++ arrays, QVectors can be resized at any time by    calling resize(). If the new size is larger than the old size,    QVector might need to reallocate the whole vector. QVector tries    to reduce the number of reallocations by preallocating up to twice    as much memory as the actual data needs.    If you know in advance approximately how many items the QVector    will contain, you can call reserve(), asking QVector to    preallocate a certain amount of memory. You can also call    capacity() to find out how much memory QVector actually    allocated.    QVector'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, indexOf() and lastIndexOf() expect the value type to    support \c operator==(). These requirements are documented on a    per-function basis.    Like the other container classes, QVector provides \l{Java-style    iterators} (QVectorIterator and QMutableVectorIterator) and    \l{STL-style iterators} (QVector::const_iterator and    QVector::iterator). In practice, these are rarely used, because    you can use indexes into the QVector.    In addition to QVector, Qt also provides QVarLengthArray, a very    low-level class with little functionality that is optimized for    speed.    QVector does \e not support inserting, prepending, appending or replacing    with references to its own values. Doing so will cause your application to    abort with an error message.    \sa QVectorIterator, QMutableVectorIterator, QList, QLinkedList*//*!    \fn QVector<T> QVector::mid(int pos, int length = -1) const    Returns a vector whose elements are copied from this vector,    starting at position \a pos. If \a length is -1 (the default), all    elements after \a pos are copied; otherwise \a length elements (or    all remaining elements if there are less than \a length elements)    are copied.*//*! \fn QVector::QVector()    Constructs an empty vector.    \sa resize()*//*! \fn QVector::QVector(int size)    Constructs a vector with an initial size of \a size elements.    The elements are initialized with a \l{default-constructed    value}.    \sa resize()*//*! \fn QVector::QVector(int size, const T &value)    Constructs a vector with an initial size of \a size elements.    Each element is initialized with \a value.    \sa resize(), fill()*//*! \fn QVector::QVector(const QVector<T> &other)    Constructs a copy of \a other.    This operation takes \l{constant time}, because QVector is    \l{implicitly shared}. This makes returning a QVector from a    function very fast. If a shared instance is modified, it will be    copied (copy-on-write), and that takes \l{linear time}.    \sa operator=()*//*! \fn QVector::~QVector()    Destroys the vector.*//*! \fn QVector<T> &QVector::operator=(const QVector<T> &other)    Assigns \a other to this vector and returns a reference to this    vector.*//*! \fn bool QVector::operator==(const QVector<T> &other) const    Returns true if \a other is equal to this vector; otherwise    returns false.    Two vectors are considered equal if they contain the same values    in the same order.    This function requires the value type to have an implementation    of \c operator==().    \sa operator!=()*//*! \fn bool QVector::operator!=(const QVector<T> &other) const    Returns true if \a other is not equal to this vector; otherwise    returns false.    Two vectors are considered equal if they contain the same values    in the same order.    This function requires the value type to have an implementation    of \c operator==().    \sa operator==()*//*! \fn int QVector::size() const    Returns the number of items in the vector.    \sa isEmpty(), resize()*//*! \fn bool QVector::isEmpty() const    Returns true if the vector has size 0; otherwise returns false.    \sa size(), resize()*//*! \fn void QVector::resize(int size)    Sets the size of the vector to \a size. If \a size is greater than the    current size, elements are added to the end; the new elements are    initialized with a \l{default-constructed value}. If \a size is less    than the current size, elements are removed from the end.    \sa size()*//*! \fn int QVector::capacity() const    Returns the maximum number of items that can be stored in the    vector without forcing a reallocation.    The sole purpose of this function is to provide a means of fine    tuning QVector's memory usage. In general, you will rarely ever    need to call this function. If you want to know how many items are    in the vector, call size().    \sa reserve(), squeeze()*//*! \fn void QVector::reserve(int size)    Attempts to allocate memory for at least \a size elements. If you    know in advance how large the vector will be, you can call this    function, and if you call resize() often you are likely to get    better performance. If \a size is an underestimate, the worst    that will happen is that the QVector will be a bit slower.    The sole purpose of this function is to provide a means of fine    tuning QVector's memory usage. In general, you will rarely ever    need to call this function. If you want to change the size of the    vector, call resize().    \sa squeeze(), capacity()*//*! \fn void QVector::squeeze()    Releases any memory not required to store the items.    The sole purpose of this function is to provide a means of fine    tuning QVector's memory usage. In general, you will rarely ever    need to call this function.    \sa reserve(), capacity()*//*! \fn void QVector::detach()    \internal*//*! \fn bool QVector::isDetached() const    \internal*//*! \fn void QVector::setSharable(bool sharable)    \internal*//*! \fn T *QVector::data()    Returns a pointer to the data stored in the vector. The pointer    can be used to access and modify the items in the vector.    Example:    \code        QVector<int> vector(10);        int *data = vector.data();        for (int i = 0; i < 10; ++i)            data[i] = 2 * i;    \endcode    The pointer remains valid as long as the vector isn't    reallocated.    This function is mostly useful to pass a vector to a function    that accepts a plain C++ array.    \sa constData(), operator[]()*//*! \fn const T *QVector::data() const    \overload*//*! \fn const T *QVector::constData() const    Returns a const pointer to the data stored in the vector. The    pointer can be used to access the items in the vector.    The pointer remains valid as long as the vector isn't    reallocated.    This function is mostly useful to pass a vector to a function    that accepts a plain C++ array.    \sa data(), operator[]()*//*! \fn void QVector::clear()    Removes all the elements from the vector.    Same as resize(0).*//*! \fn const T &QVector::at(int i) const    Returns the item at index position \a i in the vector.    \a i must be a valid index position in the vector (i.e., 0 <= \a    i < size()).    \sa value(), operator[]()*//*! \fn T &QVector::operator[](int i)    Returns the item at index position \a i as a modifiable reference.    \a i must be a valid index position in the vector (i.e., 0 <= \a i    < size()).    \sa at(), value()*//*! \fn const T &QVector::operator[](int i) const    \overload    Same as at(\a i).*//*! \fn void QVector::append(const T &value)    Inserts \a value at the end of the vector.    Example:    \code        QVector<QString> vector(0);        vector.append("one");        vector.append("two");        vector.append("three");        // vector: ["one", "two", three"]    \endcode    This is the same as calling resize(size() + 1) and assigning \a    value to the new last element in the vector.    This operation is relatively fast, because QVector typically    allocates more memory than necessary, so it can grow without    reallocating the entire vector each time.    \sa operator<<(), prepend(), insert()*//*! \fn void QVector::prepend(const T &value)    Inserts \a value at the beginning of the vector.    Example:    \code        QVector<QString> vector;        vector.prepend("one");        vector.prepend("two");        vector.prepend("three");        // vector: ["three", "two", "one"]    \endcode    This is the same as vector.insert(0, \a value).    For large vectors, this operation can be slow (\l{linear time}),    because it requires moving all the items in the vector by one    position further in memory. If you want a container class that    provides a fast prepend() function, use QList or QLinkedList    instead.    \sa append(), insert()*//*! \fn void QVector::insert(int i, const T &value)    Inserts \a value at index position \a i in the vector. If \a i is    0, the value is prepended to the vector. If \a i is size(), the    value is appended to the vector.    Example:    \code        QVector<QString> vector;        vector << "alpha" << "beta" << "delta";        vector.insert(2, "gamma");        // vector: ["alpha", "beta", "gamma", "delta"]    \endcode    For large vectors, this operation can be slow (\l{linear time}),    because it requires moving all the items at indexes \a i and    above by one position further in memory. If you want a container    class that provides a fast insert() function, use QLinkedList    instead.    \sa append(), prepend(), remove()*//*! \fn void QVector::insert(int i, int count, const T &value)