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diff --git a/src/corelib/tools/qlist.cpp b/src/corelib/tools/qlist.cpp new file mode 100644 index 0000000..0993681 --- /dev/null +++ b/src/corelib/tools/qlist.cpp @@ -0,0 +1,1752 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the QtCore module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain +** additional rights. These rights are described in the Nokia Qt LGPL +** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this +** package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 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 the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at http://qt.nokia.com/contact. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "qlist.h" +#include "qtools_p.h" +#include <string.h> + +QT_BEGIN_NAMESPACE + +/* + QList as an array-list combines the easy-of-use of a random + access interface with fast list operations and the low memory + management overhead of an array. Accessing elements by index, + appending, prepending, and removing elements from both the front + and the back all happen in constant time O(1). Inserting or + removing elements at random index positions \ai happens in linear + time, or more precisly in O(min{i,n-i}) <= O(n/2), with n being + the number of elements in the list. +*/ + +QListData::Data QListData::shared_null = { Q_BASIC_ATOMIC_INITIALIZER(1), 0, 0, 0, true, { 0 } }; + +static int grow(int size) +{ + // dear compiler: don't optimize me out. + volatile int x = qAllocMore(size * sizeof(void *), QListData::DataHeaderSize) / sizeof(void *); + return x; +} + +#if QT_VERSION >= 0x050000 +# error "Remove QListData::detach(), it is only required for binary compatibility for 4.0.x to 4.2.x" +#endif +QListData::Data *QListData::detach() +{ + Data *x = static_cast<Data *>(qMalloc(DataHeaderSize + d->alloc * sizeof(void *))); + if (!x) + qFatal("QList: Out of memory"); + + ::memcpy(x, d, DataHeaderSize + d->alloc * sizeof(void *)); + x->alloc = d->alloc; + x->ref = 1; + x->sharable = true; + if (!x->alloc) + x->begin = x->end = 0; + + qSwap(d, x); + if (!x->ref.deref()) + return x; + return 0; +} + +// Returns the old (shared) data, it is up to the caller to deref() and free() +QListData::Data *QListData::detach2() +{ + Data *x = d; + d = static_cast<Data *>(qMalloc(DataHeaderSize + x->alloc * sizeof(void *))); + if (!d) + qFatal("QList: Out of memory"); + + ::memcpy(d, x, DataHeaderSize + x->alloc * sizeof(void *)); + d->alloc = x->alloc; + d->ref = 1; + d->sharable = true; + if (!d->alloc) + d->begin = d->end = 0; + + return x; +} + +void QListData::realloc(int alloc) +{ + Q_ASSERT(d->ref == 1); + Data *x = static_cast<Data *>(qRealloc(d, DataHeaderSize + alloc * sizeof(void *))); + if (!x) + qFatal("QList: Out of memory"); + + d = x; + d->alloc = alloc; + if (!alloc) + d->begin = d->end = 0; +} + +void **QListData::append() +{ + Q_ASSERT(d->ref == 1); + if (d->end == d->alloc) { + int n = d->end - d->begin; + if (d->begin > 2 * d->alloc / 3) { + ::memcpy(d->array + n, d->array + d->begin, n * sizeof(void *)); + d->begin = n; + d->end = n * 2; + } else { + realloc(grow(d->alloc + 1)); + } + } + return d->array + d->end++; +} + +void **QListData::append(const QListData& l) +{ + Q_ASSERT(d->ref == 1); + int e = d->end; + int n = l.d->end - l.d->begin; + if (n) { + if (e + n > d->alloc) + realloc(grow(e + l.d->end - l.d->begin)); + ::memcpy(d->array + d->end, l.d->array + l.d->begin, n * sizeof(void*)); + d->end += n; + } + return d->array + e; +} + +void **QListData::prepend() +{ + Q_ASSERT(d->ref == 1); + if (d->begin == 0) { + if (d->end >= d->alloc / 3) + realloc(grow(d->alloc + 1)); + + if (d->end < d->alloc / 3) + d->begin = d->alloc - 2 * d->end; + else + d->begin = d->alloc - d->end; + + ::memmove(d->array + d->begin, d->array, d->end * sizeof(void *)); + d->end += d->begin; + } + return d->array + --d->begin; +} + +void **QListData::insert(int i) +{ + Q_ASSERT(d->ref == 1); + if (i <= 0) + return prepend(); + if (i >= d->end - d->begin) + return append(); + + bool leftward = false; + int size = d->end - d->begin; + + if (d->begin == 0) { + if (d->end == d->alloc) { + // If the array is full, we expand it and move some items rightward + realloc(grow(d->alloc + 1)); + } else { + // If there is free space at the end of the array, we move some items rightward + } + } else { + if (d->end == d->alloc) { + // If there is free space at the beginning of the array, we move some items leftward + leftward = true; + } else { + // If there is free space at both ends, we move as few items as possible + leftward = (i < size - i); + } + } + + if (leftward) { + --d->begin; + ::memmove(d->array + d->begin, d->array + d->begin + 1, i * sizeof(void *)); + } else { + ::memmove(d->array + d->begin + i + 1, d->array + d->begin + i, + (size - i) * sizeof(void *)); + ++d->end; + } + return d->array + d->begin + i; +} + +void QListData::remove(int i) +{ + Q_ASSERT(d->ref == 1); + i += d->begin; + if (i - d->begin < d->end - i) { + if (int offset = i - d->begin) + ::memmove(d->array + d->begin + 1, d->array + d->begin, offset * sizeof(void *)); + d->begin++; + } else { + if (int offset = d->end - i - 1) + ::memmove(d->array + i, d->array + i + 1, offset * sizeof(void *)); + d->end--; + } +} + +void QListData::remove(int i, int n) +{ + Q_ASSERT(d->ref == 1); + i += d->begin; + int middle = i + n/2; + if (middle - d->begin < d->end - middle) { + ::memmove(d->array + d->begin + n, d->array + d->begin, + (i - d->begin) * sizeof(void*)); + d->begin += n; + } else { + ::memmove(d->array + i, d->array + i + n, + (d->end - i - n) * sizeof(void*)); + d->end -= n; + } +} + +void QListData::move(int from, int to) +{ + Q_ASSERT(d->ref == 1); + if (from == to) + return; + + from += d->begin; + to += d->begin; + void *t = d->array[from]; + + if (from < to) { + if (d->end == d->alloc || 3 * (to - from) < 2 * (d->end - d->begin)) { + ::memmove(d->array + from, d->array + from + 1, (to - from) * sizeof(void *)); + } else { + // optimization + if (int offset = from - d->begin) + ::memmove(d->array + d->begin + 1, d->array + d->begin, offset * sizeof(void *)); + if (int offset = d->end - (to + 1)) + ::memmove(d->array + to + 2, d->array + to + 1, offset * sizeof(void *)); + ++d->begin; + ++d->end; + ++to; + } + } else { + if (d->begin == 0 || 3 * (from - to) < 2 * (d->end - d->begin)) { + ::memmove(d->array + to + 1, d->array + to, (from - to) * sizeof(void *)); + } else { + // optimization + if (int offset = to - d->begin) + ::memmove(d->array + d->begin - 1, d->array + d->begin, offset * sizeof(void *)); + if (int offset = d->end - (from + 1)) + ::memmove(d->array + from, d->array + from + 1, offset * sizeof(void *)); + --d->begin; + --d->end; + --to; + } + } + d->array[to] = t; +} + +void **QListData::erase(void **xi) +{ + Q_ASSERT(d->ref == 1); + int i = xi - (d->array + d->begin); + remove(i); + return d->array + d->begin + i; +} + +/*! \class QList + \brief The QList class is a template class that provides lists. + + \ingroup tools + \ingroup shared + + \reentrant + + QList\<T\> is one of Qt's generic \l{container classes}. It + stores a list of values and provides fast index-based access as + well as fast 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. 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 + + + Internally, QList\<T\> is represented as an array of pointers to + items of type T. If T is itself a pointer type or a basic type + that is no larger than a pointer, or if T is one of Qt's \l{shared + classes}, then QList\<T\> stores the items directly in the pointer + array. For lists under a thousand items, this array representation + allows for very fast insertions in the middle, and it allows + index-based access. Furthermore, operations like prepend() and + append() are very fast, because QList preallocates memory at both + ends of its internal array. (See \l{Algorithmic Complexity} for + details.) Note, however, that for unshared list items that are + larger than a pointer, each append or insert of a new item + requires allocating the new item on the heap, and this per item + allocation might make QVector a better choice in cases that do + lots of appending or inserting, since QVector allocates memory for + its items in a single heap allocation. + + Note that the internal array only ever gets bigger over the life + of the list. It never shrinks. The internal array is deallocated + by the destructor and by the assignment operator, when one list + is assigned to another. + + Here's an example of a QList that stores integers and + a QList that stores QDate values: + + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 0 + + Qt includes a QStringList class that inherits QList\<QString\> + and adds a few convenience functions, such as QStringList::join() + and QStringList::find(). (QString::split() creates QStringLists + from strings.) + + QList stores a list of items. The default constructor creates an + empty list. To insert items into the list, you can use + operator<<(): + + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 1 + + QList provides these basic functions to add, move, and remove + items: insert(), replace(), removeAt(), move(), and swap(). In + addition, it provides the following convenience functions: + append(), prepend(), removeFirst(), and removeLast(). + + QList uses 0-based indexes, just like C++ arrays. To access the + item at a particular index position, you can use operator[](). On + non-const lists, operator[]() returns a reference to the item and + can be used on the left side of an assignment: + + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 2 + + Because QList is implemented as an array of pointers, this + operation is very fast (\l{constant time}). For read-only access, + an alternative syntax is to use at(): + + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 3 + + at() can be faster than operator[](), because it never causes a + \l{deep copy} to occur. + + A common requirement is to remove an item from a list and do + something with it. For this, QList provides takeAt(), takeFirst(), + and takeLast(). Here's a loop that removes the items from a list + one at a time and calls \c delete on them: + + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 4 + + Inserting and removing items at either ends of the list is very + fast (\l{constant time} in most cases), because QList + preallocates extra space on both sides of its internal buffer to + allow for fast growth at both ends of the list. + + If you want to find all occurrences of a particular value in a + list, use indexOf() or lastIndexOf(). The former searches forward + starting from a given index position, the latter searches + backward. Both return the index of a matching item if they find + it; otherwise, they return -1. For example: + + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 5 + + If you simply want to check whether a list contains a particular + value, use contains(). If you want to find out how many times a + particular value occurs in the list, use count(). If you want to + replace all occurrences of a particular value with another, use + replace(). + + QList'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, QList provides \l{Java-style + iterators} (QListIterator and QMutableListIterator) and + \l{STL-style iterators} (QList::const_iterator and + QList::iterator). In practice, these are rarely used, because you + can use indexes into the QList. QList is implemented in such a way + that direct index-based access is just as fast as using iterators. + + QList 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. + + To make QList as efficient as possible, its member functions don't + validate their input before using it. Except for isEmpty(), member + functions always assume the list is \e not empty. Member functions + that take index values as parameters always assume their index + value parameters are in the valid range. This means QList member + functions can fail. If you define QT_NO_DEBUG when you compile, + failures will not be detected. If you \e don't define QT_NO_DEBUG, + failures will be detected using Q_ASSERT() or Q_ASSERT_X() with an + appropriate message. + + To avoid failures when your list can be empty, call isEmpty() + before calling other member functions. If you must pass an index + value that might not be in the valid range, check that it is less + than the value returned by size() but \e not less than 0. + + \sa QListIterator, QMutableListIterator, QLinkedList, QVector +*/ + +/*! + \fn QList<T> QList<T>::mid(int pos, int length) const + + Returns a list whose elements are copied from this list, + starting at position \a pos. If \a length is -1 (the default), all + elements from \a pos are copied; otherwise \a length elements (or + all remaining elements if there are less than \a length elements) + are copied. +*/ + +/*! \fn QList::QList() + + Constructs an empty list. +*/ + +/*! \fn QList::QList(const QList<T> &other) + + Constructs a copy of \a other. + + This operation takes \l{constant time}, because QList is + \l{implicitly shared}. This makes returning a QList 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 QList::~QList() + + Destroys the list. References to the values in the list and all + iterators of this list become invalid. +*/ + +/*! \fn QList<T> &QList::operator=(const QList<T> &other) + + Assigns \a other to this list and returns a reference to this + list. +*/ + +/*! \fn bool QList::operator==(const QList<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 have an implementation of + \c operator==(). + + \sa operator!=() +*/ + +/*! \fn bool QList::operator!=(const QList<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 have an implementation of + \c operator==(). + + \sa operator==() +*/ + +/*! + \fn int QList::size() const + + Returns the number of items in the list. + + \sa isEmpty(), count() +*/ + +/*! \fn void QList::detach() + + \internal +*/ + +/*! \fn bool QList::isDetached() const + + \internal +*/ + +/*! \fn void QList::setSharable(bool sharable) + + \internal +*/ + +/*! \fn bool QList::isEmpty() const + + Returns true if the list contains no items; otherwise returns + false. + + \sa size() +*/ + +/*! \fn void QList::clear() + + Removes all items from the list. + + \sa removeAll() +*/ + +/*! \fn const T &QList::at(int i) const + + Returns the item at index position \a i in the list. \a i must be + a valid index position in the list (i.e., 0 <= \a i < size()). + + This function is very fast (\l{constant time}). + + \sa value(), operator[]() +*/ + +/*! \fn T &QList::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 list (i.e., 0 <= \a i < + size()). + + This function is very fast (\l{constant time}). + + \sa at(), value() +*/ + +/*! \fn const T &QList::operator[](int i) const + + \overload + + Same as at(). +*/ + +/*! \fn void QList::append(const T &value) + + Inserts \a value at the end of the list. + + Example: + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 6 + + This is the same as list.insert(size(), \a value). + + This operation is typically very fast (\l{constant time}), + because QList preallocates extra space on both sides of its + internal buffer to allow for fast growth at both ends of the + list. + + \sa operator<<(), prepend(), insert() +*/ + +/*! \fn void QList::append(const QList<T> &value) + + \overload + + \since 4.5 + + Appends the items of the \a value list to this list. + + \sa operator<<(), operator+=() +*/ + +/*! \fn void QList::prepend(const T &value) + + Inserts \a value at the beginning of the list. + + Example: + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 7 + + This is the same as list.insert(0, \a value). + + This operation is usually very fast (\l{constant time}), because + QList preallocates extra space on both sides of its internal + buffer to allow for fast growth at both ends of the list. + + \sa append(), insert() +*/ + +/*! \fn void QList::insert(int i, const T &value) + + Inserts \a value at index position \a i in the list. If \a i + is 0, the value is prepended to the list. If \a i is size(), the + value is appended to the list. + + Example: + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 8 + + \sa append(), prepend(), replace(), removeAt() +*/ + +/*! \fn QList::iterator QList::insert(iterator before, const T &value) + + \overload + + Inserts \a value in front of the item pointed to by the + iterator \a before. Returns an iterator pointing at the inserted + item. Note that the iterator passed to the function will be + invalid after the call; the returned iterator should be used + instead. +*/ + +/*! \fn void QList::replace(int i, const T &value) + + Replaces the item at index position \a i with \a value. \a i must + be a valid index position in the list (i.e., 0 <= \a i < size()). + + \sa operator[](), removeAt() +*/ + +/*! + \fn int QList::removeAll(const T &value) + + Removes all occurrences of \a value in the list and returns the + number of entries removed. + + Example: + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 9 + + This function requires the value type to have an implementation of + \c operator==(). + + \sa removeOne(), removeAt(), takeAt(), replace() +*/ + +/*! + \fn bool QList::removeOne(const T &value) + \since 4.4 + + Removes the first occurrence of \a value in the list and returns + true on success; otherwise returns false. + + Example: + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 10 + + This function requires the value type to have an implementation of + \c operator==(). + + \sa removeAll(), removeAt(), takeAt(), replace() +*/ + +/*! \fn void QList::removeAt(int i) + + Removes the item at index position \a i. \a i must be a valid + index position in the list (i.e., 0 <= \a i < size()). + + \sa takeAt(), removeFirst(), removeLast(), removeOne() +*/ + +/*! \fn T QList::takeAt(int i) + + Removes the item at index position \a i and returns it. \a i must + be a valid index position in the list (i.e., 0 <= \a i < size()). + + If you don't use the return value, removeAt() is more efficient. + + \sa removeAt(), takeFirst(), takeLast() +*/ + +/*! \fn T QList::takeFirst() + + Removes the first item in the list and returns it. This is the + same as takeAt(0). This function assumes the list is not empty. To + avoid failure, call isEmpty() before calling this function. + + This operation is very fast (\l{constant time}), because QList + preallocates extra space on both sides of its internal buffer to + allow for fast growth at both ends of the list. + + If you don't use the return value, removeFirst() is more + efficient. + + \sa takeLast(), takeAt(), removeFirst() +*/ + +/*! \fn T QList::takeLast() + + Removes the last item in the list and returns it. This is the + same as takeAt(size() - 1). This function assumes the list is + not empty. To avoid failure, call isEmpty() before calling this + function. + + This operation is very fast (\l{constant time}), because QList + preallocates extra space on both sides of its internal buffer to + allow for fast growth at both ends of the list. + + If you don't use the return value, removeLast() is more + efficient. + + \sa takeFirst(), takeAt(), removeLast() +*/ + +/*! \fn void QList::move(int from, int to) + + Moves the item at index position \a from to index position \a to. + + Example: + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 11 + + This is the same as insert(\a{to}, takeAt(\a{from})).This function + assumes that both \a from and \a to are at least 0 but less than + size(). To avoid failure, test that both \a from and \a to are at + least 0 and less than size(). + + \sa swap(), insert(), takeAt() +*/ + +/*! \fn void QList::swap(int i, int j) + + Exchange the item at index position \a i with the item at index + position \a j. This function assumes that both \a i and \a j are + at least 0 but less than size(). To avoid failure, test that both + \a i and \a j are at least 0 and less than size(). + + Example: + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 12 + + \sa move() +*/ + +/*! \fn int QList::indexOf(const T &value, int from = 0) const + + Returns the index position of the first occurrence of \a value in + the list, searching forward from index position \a from. Returns + -1 if no item matched. + + Example: + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 13 + + This function requires the value type to have an implementation of + \c operator==(). + + Note that QList uses 0-based indexes, just like C++ arrays. Negative + indexes are not supported with the exception of the value mentioned + above. + + \sa lastIndexOf(), contains() +*/ + +/*! \fn int QList::lastIndexOf(const T &value, int from = -1) const + + Returns the index position of the last occurrence of \a value in + the list, searching backward from index position \a from. If \a + from is -1 (the default), the search starts at the last item. + Returns -1 if no item matched. + + Example: + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 14 + + This function requires the value type to have an implementation of + \c operator==(). + + Note that QList uses 0-based indexes, just like C++ arrays. Negative + indexes are not supported with the exception of the value mentioned + above. + + \sa indexOf() +*/ + +/*! \fn QBool QList::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 indexOf(), count() +*/ + +/*! \fn int QList::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(), indexOf() +*/ + +/*! \fn bool QList::startsWith(const T &value) const + \since 4.5 + + Returns true if this list is not empty and its first + item is equal to \a value; otherwise returns false. + + \sa isEmpty(), contains() +*/ + +/*! \fn bool QList::endsWith(const T &value) const + \since 4.5 + + Returns true if this list is not empty and its last + item is equal to \a value; otherwise returns false. + + \sa isEmpty(), contains() +*/ + +/*! \fn QList::iterator QList::begin() + + Returns an \l{STL-style iterator} pointing to the first item in + the list. + + \sa constBegin(), end() +*/ + +/*! \fn QList::const_iterator QList::begin() const + + \overload +*/ + +/*! \fn QList::const_iterator QList::constBegin() const + + Returns a const \l{STL-style iterator} pointing to the first item + in the list. + + \sa begin(), constEnd() +*/ + +/*! \fn QList::iterator QList::end() + + Returns an \l{STL-style iterator} pointing to the imaginary item + after the last item in the list. + + \sa begin(), constEnd() +*/ + +/*! \fn const_iterator QList::end() const + + \overload +*/ + +/*! \fn QList::const_iterator QList::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 QList::iterator QList::erase(iterator pos) + + Removes the item associated with the iterator \a pos from the + list, and returns an iterator to the next item in the list (which + may be end()). + + \sa insert(), removeAt() +*/ + +/*! \fn QList::iterator QList::erase(iterator begin, iterator end) + + \overload + + Removes all the items from \a begin up to (but not including) \a + end. Returns an iterator to the same item that \a end referred to + before the call. +*/ + +/*! \typedef QList::Iterator + + Qt-style synonym for QList::iterator. +*/ + +/*! \typedef QList::ConstIterator + + Qt-style synonym for QList::const_iterator. +*/ + +/*! + \typedef QList::size_type + + Typedef for int. Provided for STL compatibility. +*/ + +/*! + \typedef QList::value_type + + Typedef for T. Provided for STL compatibility. +*/ + +/*! + \typedef QList::difference_type + + Typedef for ptrdiff_t. Provided for STL compatibility. +*/ + +/*! + \typedef QList::pointer + + Typedef for T *. Provided for STL compatibility. +*/ + +/*! + \typedef QList::const_pointer + + Typedef for const T *. Provided for STL compatibility. +*/ + +/*! + \typedef QList::reference + + Typedef for T &. Provided for STL compatibility. +*/ + +/*! + \typedef QList::const_reference + + Typedef for const T &. Provided for STL compatibility. +*/ + +/*! \fn int QList::count() const + + Returns the number of items in the list. This is effectively the + same as size(). +*/ + +/*! \fn int QList::length() const + \since 4.5 + + This function is identical to count(). + + \sa count() +*/ + +/*! \fn T& QList::first() + + Returns a reference to the first item in the list. The list must + not be empty. If the list can be empty, call isEmpty() before + calling this function. + + \sa last(), isEmpty() +*/ + +/*! \fn const T& QList::first() const + + \overload +*/ + +/*! \fn T& QList::last() + + Returns a reference to the last item in the list. The list must + not be empty. If the list can be empty, call isEmpty() before + calling this function. + + \sa first(), isEmpty() +*/ + +/*! \fn const T& QList::last() const + + \overload +*/ + +/*! \fn void QList::removeFirst() + + Removes the first item in the list. Calling this function is + equivalent to calling removeAt(0). The list must not be empty. If + the list can be empty, call isEmpty() before calling this + function. + + \sa removeAt(), takeFirst() +*/ + +/*! \fn void QList::removeLast() + + Removes the last item in the list. Calling this function is + equivalent to calling removeAt(size() - 1). The list must not be + empty. If the list can be empty, call isEmpty() before calling + this function. + + \sa removeAt(), takeLast() +*/ + +/*! \fn T QList::value(int i) const + + Returns the value at index position \a i in the list. + + If the index \a i is out of bounds, the function returns a + \l{default-constructed value}. If you are certain that the index + is going to be within bounds, you can use at() instead, which is + slightly faster. + + \sa at(), operator[]() +*/ + +/*! \fn T QList::value(int i, const T &defaultValue) const + + \overload + + If the index \a i is out of bounds, the function returns + \a defaultValue. +*/ + +/*! \fn void QList::push_back(const T &value) + + This function is provided for STL compatibility. It is equivalent + to \l{QList::append()}{append(\a value)}. +*/ + +/*! \fn void QList::push_front(const T &value) + + This function is provided for STL compatibility. It is equivalent + to \l{QList::prepend()}{prepend(\a value)}. +*/ + +/*! \fn T& QList::front() + + This function is provided for STL compatibility. It is equivalent + to first(). The list must not be empty. If the list can be empty, + call isEmpty() before calling this function. +*/ + +/*! \fn const T& QList::front() const + + \overload +*/ + +/*! \fn T& QList::back() + + This function is provided for STL compatibility. It is equivalent + to last(). The list must not be empty. If the list can be empty, + call isEmpty() before calling this function. +*/ + +/*! \fn const T& QList::back() const + + \overload +*/ + +/*! \fn void QList::pop_front() + + This function is provided for STL compatibility. It is equivalent + to removeFirst(). The list must not be empty. If the list can be + empty, call isEmpty() before calling this function. +*/ + +/*! \fn void QList::pop_back() + + This function is provided for STL compatibility. It is equivalent + to removeLast(). The list must not be empty. If the list can be + empty, call isEmpty() before calling this function. +*/ + +/*! \fn bool QList::empty() const + + This function is provided for STL compatibility. It is equivalent + to isEmpty() and returns true if the list is empty. +*/ + +/*! \fn QList<T> &QList::operator+=(const QList<T> &other) + + Appends the items of the \a other list to this list and returns a + reference to this list. + + \sa operator+(), append() +*/ + +/*! \fn void QList::operator+=(const T &value) + + \overload + + Appends \a value to the list. + + \sa append(), operator<<() +*/ + +/*! \fn QList<T> QList::operator+(const QList<T> &other) const + + Returns a list that contains all the items in this list followed + by all the items in the \a other list. + + \sa operator+=() +*/ + +/*! \fn QList<T> &QList::operator<<(const QList<T> &other) + + Appends the items of the \a other list to this list and returns a + reference to this list. + + \sa operator+=(), append() +*/ + +/*! \fn void QList::operator<<(const T &value) + + \overload + + Appends \a value to the list. +*/ + +/*! \class QList::iterator + \brief The QList::iterator class provides an STL-style non-const iterator for QList and QQueue. + + QList features both \l{STL-style iterators} and \l{Java-style + iterators}. The STL-style iterators are more low-level and more + cumbersome to use; on the other hand, they are slightly faster + and, for developers who already know STL, have the advantage of + familiarity. + + QList\<T\>::iterator allows you to iterate over a QList\<T\> (or + QQueue\<T\>) and to modify the list item associated with the + iterator. If you want to iterate over a const QList, use + QList::const_iterator instead. It is generally good practice to + use QList::const_iterator on a non-const QList as well, unless + you need to change the QList through the iterator. Const + iterators are slightly faster, and can improve code readability. + + The default QList::iterator constructor creates an uninitialized + iterator. You must initialize it using a QList function like + QList::begin(), QList::end(), or QList::insert() before you can + start iterating. Here's a typical loop that prints all the items + stored in a list: + + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 15 + + Let's see a few examples of things we can do with a + QList::iterator that we cannot do with a QList::const_iterator. + Here's an example that increments every value stored in a + QList\<int\> by 2: + + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 16 + + Most QList functions accept an integer index rather than an + iterator. For that reason, iterators are rarely useful in + connection with QList. One place where STL-style iterators do + make sense is as arguments to \l{generic algorithms}. + + For example, here's how to delete all the widgets stored in a + QList\<QWidget *\>: + + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 17 + + Multiple iterators can be used on the same list. However, be + aware that any non-const function call performed on the QList + will render all existing iterators undefined. If you need to keep + iterators over a long period of time, we recommend that you use + QLinkedList rather than QList. + + \sa QList::const_iterator, QMutableListIterator +*/ + +/*! \typedef QList::iterator::iterator_category + + A synonym for \e {std::random_access_iterator_tag} indicating + this iterator is a random access iterator. +*/ + +/*! \typedef QList::iterator::difference_type + + \internal +*/ + +/*! \typedef QList::iterator::value_type + + \internal +*/ + +/*! \typedef QList::iterator::pointer + + \internal +*/ + +/*! \typedef QList::iterator::reference + + \internal +*/ + +/*! \fn QList::iterator::iterator() + + Constructs an uninitialized iterator. + + Functions like operator*() and operator++() should not be called + on an uninitialized iterator. Use operator=() to assign a value + to it before using it. + + \sa QList::begin() QList::end() +*/ + +/*! \fn QList::iterator::iterator(Node *node) + + \internal +*/ + +/*! \fn QList::iterator::iterator(const iterator &other) + + Constructs a copy of \a other. +*/ + +/*! \fn T &QList::iterator::operator*() const + + Returns a modifiable reference to the current item. + + You can change the value of an item by using operator*() on the + left side of an assignment, for example: + + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 18 + + \sa operator->() +*/ + +/*! \fn T *QList::iterator::operator->() const + + Returns a pointer to the current item. + + \sa operator*() +*/ + +/*! \fn T &QList::iterator::operator[](int j) const + + Returns a modifiable reference to the item at position *this + + \a{j}. + + This function is provided to make QList iterators behave like C++ + pointers. + + \sa operator+() +*/ + +/*! + \fn bool QList::iterator::operator==(const iterator &other) const + \fn bool QList::iterator::operator==(const const_iterator &other) const + + Returns true if \a other points to the same item as this + iterator; otherwise returns false. + + \sa operator!=() +*/ + +/*! + \fn bool QList::iterator::operator!=(const iterator &other) const + \fn bool QList::iterator::operator!=(const const_iterator &other) const + + Returns true if \a other points to a different item than this + iterator; otherwise returns false. + + \sa operator==() +*/ + +/*! + \fn bool QList::iterator::operator<(const iterator& other) const + \fn bool QList::iterator::operator<(const const_iterator& other) const + + Returns true if the item pointed to by this iterator is less than + the item pointed to by the \a other iterator. +*/ + +/*! + \fn bool QList::iterator::operator<=(const iterator& other) const + \fn bool QList::iterator::operator<=(const const_iterator& other) const + + Returns true if the item pointed to by this iterator is less than + or equal to the item pointed to by the \a other iterator. +*/ + +/*! + \fn bool QList::iterator::operator>(const iterator& other) const + \fn bool QList::iterator::operator>(const const_iterator& other) const + + Returns true if the item pointed to by this iterator is greater + than the item pointed to by the \a other iterator. +*/ + +/*! + \fn bool QList::iterator::operator>=(const iterator& other) const + \fn bool QList::iterator::operator>=(const const_iterator& other) const + + Returns true if the item pointed to by this iterator is greater + than or equal to the item pointed to by the \a other iterator. +*/ + +/*! \fn QList::iterator &QList::iterator::operator++() + + The prefix ++ operator (\c{++it}) advances the iterator to the + next item in the list and returns an iterator to the new current + item. + + Calling this function on QList::end() leads to undefined results. + + \sa operator--() +*/ + +/*! \fn QList::iterator QList::iterator::operator++(int) + + \overload + + The postfix ++ operator (\c{it++}) advances the iterator to the + next item in the list and returns an iterator to the previously + current item. +*/ + +/*! \fn QList::iterator &QList::iterator::operator--() + + The prefix -- operator (\c{--it}) makes the preceding item + current and returns an iterator to the new current item. + + Calling this function on QList::begin() leads to undefined results. + + \sa operator++() +*/ + +/*! \fn QList::iterator QList::iterator::operator--(int) + + \overload + + The postfix -- operator (\c{it--}) makes the preceding item + current and returns an iterator to the previously current item. +*/ + +/*! \fn QList::iterator &QList::iterator::operator+=(int j) + + Advances the iterator by \a j items. (If \a j is negative, the + iterator goes backward.) + + \sa operator-=(), operator+() +*/ + +/*! \fn QList::iterator &QList::iterator::operator-=(int j) + + Makes the iterator go back by \a j items. (If \a j is negative, + the iterator goes forward.) + + \sa operator+=(), operator-() +*/ + +/*! \fn QList::iterator QList::iterator::operator+(int j) const + + Returns an iterator to the item at \a j positions forward from + this iterator. (If \a j is negative, the iterator goes backward.) + + \sa operator-(), operator+=() +*/ + +/*! \fn QList::iterator QList::iterator::operator-(int j) const + + Returns an iterator to the item at \a j positions backward from + this iterator. (If \a j is negative, the iterator goes forward.) + + \sa operator+(), operator-=() +*/ + +/*! \fn int QList::iterator::operator-(iterator other) const + + Returns the number of items between the item pointed to by \a + other and the item pointed to by this iterator. +*/ + +/*! \class QList::const_iterator + \brief The QList::const_iterator class provides an STL-style const iterator for QList and QQueue. + + QList provides both \l{STL-style iterators} and \l{Java-style + iterators}. The STL-style iterators are more low-level and more + cumbersome to use; on the other hand, they are slightly faster + and, for developers who already know STL, have the advantage of + familiarity. + + QList\<T\>::const_iterator allows you to iterate over a + QList\<T\> (or a QQueue\<T\>). If you want to modify the QList as + you iterate over it, use QList::iterator instead. It is generally + good practice to use QList::const_iterator on a non-const QList + as well, unless you need to change the QList through the + iterator. Const iterators are slightly faster, and can improve + code readability. + + The default QList::const_iterator constructor creates an + uninitialized iterator. You must initialize it using a QList + function like QList::constBegin(), QList::constEnd(), or + QList::insert() before you can start iterating. Here's a typical + loop that prints all the items stored in a list: + + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 19 + + Most QList functions accept an integer index rather than an + iterator. For that reason, iterators are rarely useful in + connection with QList. One place where STL-style iterators do + make sense is as arguments to \l{generic algorithms}. + + For example, here's how to delete all the widgets stored in a + QList\<QWidget *\>: + + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 20 + + Multiple iterators can be used on the same list. However, be + aware that any non-const function call performed on the QList + will render all existing iterators undefined. If you need to keep + iterators over a long period of time, we recommend that you use + QLinkedList rather than QList. + + \sa QList::iterator, QListIterator +*/ + +/*! \fn QList::const_iterator::const_iterator() + + Constructs an uninitialized iterator. + + Functions like operator*() and operator++() should not be called + on an uninitialized iterator. Use operator=() to assign a value + to it before using it. + + \sa QList::constBegin() QList::constEnd() +*/ + +/*! \typedef QList::const_iterator::iterator_category + + A synonym for \e {std::random_access_iterator_tag} indicating + this iterator is a random access iterator. +*/ + +/*! \typedef QList::const_iterator::difference_type + + \internal +*/ + +/*! \typedef QList::const_iterator::value_type + + \internal +*/ + +/*! \typedef QList::const_iterator::pointer + + \internal +*/ + +/*! \typedef QList::const_iterator::reference + + \internal +*/ + +/*! \fn QList::const_iterator::const_iterator(Node *node) + + \internal +*/ + +/*! \fn QList::const_iterator::const_iterator(const const_iterator &other) + + Constructs a copy of \a other. +*/ + +/*! \fn QList::const_iterator::const_iterator(const iterator &other) + + Constructs a copy of \a other. +*/ + +/*! \fn const T &QList::const_iterator::operator*() const + + Returns the current item. + + \sa operator->() +*/ + +/*! \fn const T *QList::const_iterator::operator->() const + + Returns a pointer to the current item. + + \sa operator*() +*/ + +/*! \fn const T &QList::const_iterator::operator[](int j) const + + Returns the item at position *this + \a{j}. + + This function is provided to make QList iterators behave like C++ + pointers. + + \sa operator+() +*/ + +/*! \fn bool QList::const_iterator::operator==(const const_iterator &other) const + + Returns true if \a other points to the same item as this + iterator; otherwise returns false. + + \sa operator!=() +*/ + +/*! \fn bool QList::const_iterator::operator!=(const const_iterator &other) const + + Returns true if \a other points to a different item than this + iterator; otherwise returns false. + + \sa operator==() +*/ + +/*! + \fn bool QList::const_iterator::operator<(const const_iterator& other) const + + Returns true if the item pointed to by this iterator is less than + the item pointed to by the \a other iterator. +*/ + +/*! + \fn bool QList::const_iterator::operator<=(const const_iterator& other) const + + Returns true if the item pointed to by this iterator is less than + or equal to the item pointed to by the \a other iterator. +*/ + +/*! + \fn bool QList::const_iterator::operator>(const const_iterator& other) const + + Returns true if the item pointed to by this iterator is greater + than the item pointed to by the \a other iterator. +*/ + +/*! + \fn bool QList::const_iterator::operator>=(const const_iterator& other) const + + Returns true if the item pointed to by this iterator is greater + than or equal to the item pointed to by the \a other iterator. +*/ + +/*! \fn QList::const_iterator &QList::const_iterator::operator++() + + The prefix ++ operator (\c{++it}) advances the iterator to the + next item in the list and returns an iterator to the new current + item. + + Calling this function on QList::end() leads to undefined results. + + \sa operator--() +*/ + +/*! \fn QList::const_iterator QList::const_iterator::operator++(int) + + \overload + + The postfix ++ operator (\c{it++}) advances the iterator to the + next item in the list and returns an iterator to the previously + current item. +*/ + +/*! \fn QList::const_iterator &QList::const_iterator::operator--() + + The prefix -- operator (\c{--it}) makes the preceding item + current and returns an iterator to the new current item. + + Calling this function on QList::begin() leads to undefined results. + + \sa operator++() +*/ + +/*! \fn QList::const_iterator QList::const_iterator::operator--(int) + + \overload + + The postfix -- operator (\c{it--}) makes the preceding item + current and returns an iterator to the previously current item. +*/ + +/*! \fn QList::const_iterator &QList::const_iterator::operator+=(int j) + + Advances the iterator by \a j items. (If \a j is negative, the + iterator goes backward.) + + \sa operator-=(), operator+() +*/ + +/*! \fn QList::const_iterator &QList::const_iterator::operator-=(int j) + + Makes the iterator go back by \a j items. (If \a j is negative, + the iterator goes forward.) + + \sa operator+=(), operator-() +*/ + +/*! \fn QList::const_iterator QList::const_iterator::operator+(int j) const + + Returns an iterator to the item at \a j positions forward from + this iterator. (If \a j is negative, the iterator goes backward.) + + \sa operator-(), operator+=() +*/ + +/*! \fn QList::const_iterator QList::const_iterator::operator-(int j) const + + Returns an iterator to the item at \a j positions backward from + this iterator. (If \a j is negative, the iterator goes forward.) + + \sa operator+(), operator-=() +*/ + +/*! \fn int QList::const_iterator::operator-(const_iterator other) const + + Returns the number of items between the item pointed to by \a + other and the item pointed to by this iterator. +*/ + +/*! \fn QDataStream &operator<<(QDataStream &out, const QList<T> &list) + \relates QList + + Writes the list \a list to stream \a out. + + This function requires the value type to implement \c + operator<<(). + + \sa \link datastreamformat.html Format of the QDataStream operators \endlink +*/ + +/*! \fn QDataStream &operator>>(QDataStream &in, QList<T> &list) + \relates QList + + Reads a list from stream \a in into \a list. + + This function requires the value type to implement \c + operator>>(). + + \sa \link datastreamformat.html Format of the QDataStream operators \endlink +*/ + +/*! + \fn iterator QList::remove(iterator pos) + + Use erase() instead. +*/ + +/*! + \fn int QList::remove(const T &t) + + Use removeAll() instead. +*/ + +/*! + \fn int QList::findIndex(const T& t) const + + Use indexOf() instead. +*/ + +/*! + \fn iterator QList::find(const T& t) + + Use indexOf() instead. +*/ + +/*! + \fn const_iterator QList::find (const T& t) const + + Use indexOf() instead. +*/ + +/*! + \fn iterator QList::find(iterator from, const T& t) + + Use indexOf() instead. +*/ + +/*! + \fn const_iterator QList::find(const_iterator from, const T& t) const + + Use indexOf() instead. +*/ + +/*! \fn QList<T> QList<T>::fromVector(const QVector<T> &vector) + + Returns a QList object with the data contained in \a vector. + + Example: + + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 21 + + \sa fromSet(), toVector(), QVector::toList() +*/ + +/*! \fn QVector<T> QList<T>::toVector() const + + Returns a QVector object with the data contained in this QList. + + Example: + + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 22 + + \sa toSet(), fromVector(), QVector::fromList() +*/ + +/*! \fn QList<T> QList<T>::fromSet(const QSet<T> &set) + + Returns a QList object with the data contained in \a set. The + order of the elements in the QList is undefined. + + Example: + + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 23 + + \sa fromVector(), toSet(), QSet::toList(), qSort() +*/ + +/*! \fn QSet<T> QList<T>::toSet() const + + Returns a QSet object with the data contained in this QList. + Since QSet doesn't allow duplicates, the resulting QSet might be + smaller than the original list was. + + Example: + + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 24 + + \sa toVector(), fromSet(), QSet::fromList() +*/ + +/*! \fn QList<T> QList<T>::fromStdList(const std::list<T> &list) + + Returns a QList object with the data contained in \a list. The + order of the elements in the QList is the same as in \a list. + + Example: + + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 25 + + \sa toStdList(), QVector::fromStdVector() +*/ + +/*! \fn std::list<T> QList<T>::toStdList() const + + Returns a std::list object with the data contained in this QList. + Example: + + \snippet doc/src/snippets/code/src_corelib_tools_qlistdata.cpp 26 + + \sa fromStdList(), QVector::toStdVector() +*/ + +QT_END_NAMESPACE |