AuroraMiddleware/qt5base-lts
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Deprecate reverse iteration on QHash

Browse Source 
std::unordered_map only supports forward iteration for good
reasons. Align our API with this by deprecating reverse
iteration and the operator+/-() for iterators.

[ChangeLog][QtCore][QHash] Reverse iteration over QHash is now
deprecated.
[ChangeLog][Potentially Binary-Incompatible Changes] QHash's
iterator category was changed from bidirectional iterator to forward
iterator. This may cause trouble if a library uses the iterator category
to alter functionality through tag dispatching. This only applies when
compiling the library or application with
QT_DISABLE_DEPRECATED_BEFORE=0x050F00 and the other with a lower value.

Change-Id: I0fb6d017cabdef1bc508e62f76dc2fa73cd3652d
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
This commit is contained in:
Lars Knoll 2018-11-22 12:00:53 +01:00 committed by Mårten Nordheim
parent 6f8a97e480
commit dbb54805f6
3 changed files with 252 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
src/corelib/serialization/qdatastream.h
View File

@ -321,14 +321,31 @@ template <typename Container>
QDataStream &writeAssociativeContainer(QDataStream &s, const Container &c)
{
s << quint32(c.size());
#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
// Deserialization should occur in the reverse order.
// Otherwise, value() will return the least recently inserted
// value instead of the most recently inserted one.
auto it = c.constEnd();
auto begin = c.constBegin();
while (it != begin) {
QT_WARNING_PUSH
QT_WARNING_DISABLE_DEPRECATED
--it;
QT_WARNING_POP
s << it.key() << it.value();
#else
auto it = c.constBegin();
auto end = c.constEnd();
while (it != end) {
const auto rangeStart = it++;
while (it != end && rangeStart.key() == it.key())
++it;
const qint64 last = std::distance(rangeStart, it) - 1;
for (qint64 i = last; i >= 0; --i) {
auto next = std::next(rangeStart, i);
s << next.key() << next.value();
}
#endif
}
return s;

252
src/corelib/tools/qhash.h
View File

@ -325,7 +325,11 @@ public:
QHashData::Node *i;
public:
#if QT_DEPRECATED_SINCE(5, 15)
typedef std::bidirectional_iterator_tag iterator_category;
#else
typedef std::forward_iterator_tag iterator_category;
#endif
typedef qptrdiff difference_type;
typedef T value_type;
typedef T *pointer;
@ -350,21 +354,25 @@ public:
i = QHashData::nextNode(i);
return r;
}
inline iterator &operator--() {
#if QT_DEPRECATED_SINCE(5, 15)
inline QT_DEPRECATED iterator &operator--()
{
i = QHashData::previousNode(i);
return *this;
}
inline iterator operator--(int) {
inline QT_DEPRECATED iterator operator--(int)
{
iterator r = *this;
i = QHashData::previousNode(i);
return r;
}
inline iterator operator+(int j) const
inline QT_DEPRECATED iterator operator+(int j) const
{ iterator r = *this; if (j > 0) while (j--) ++r; else while (j++) --r; return r; }
inline iterator operator-(int j) const { return operator+(-j); }
inline iterator &operator+=(int j) { return *this = *this + j; }
inline iterator &operator-=(int j) { return *this = *this - j; }
friend inline iterator operator+(int j, iterator k) { return k + j; }
inline QT_DEPRECATED iterator operator-(int j) const { return operator+(-j); }
inline QT_DEPRECATED iterator &operator+=(int j) { return *this = *this + j; }
inline QT_DEPRECATED iterator &operator-=(int j) { return *this = *this - j; }
friend inline QT_DEPRECATED iterator operator+(int j, iterator k) { return k + j; }
#endif
#ifndef QT_STRICT_ITERATORS
public:
@ -384,7 +392,11 @@ public:
QHashData::Node *i;
public:
#if QT_DEPRECATED_SINCE(5, 15)
typedef std::bidirectional_iterator_tag iterator_category;
#else
typedef std::forward_iterator_tag iterator_category;
#endif
typedef qptrdiff difference_type;
typedef T value_type;
typedef const T *pointer;
@ -416,21 +428,28 @@ public:
i = QHashData::nextNode(i);
return r;
}
inline const_iterator &operator--() {
#if QT_DEPRECATED_SINCE(5, 15)
inline QT_DEPRECATED const_iterator &operator--()
{
i = QHashData::previousNode(i);
return *this;
}
inline const_iterator operator--(int) {
inline QT_DEPRECATED const_iterator operator--(int)
{
const_iterator r = *this;
i = QHashData::previousNode(i);
return r;
}
inline const_iterator operator+(int j) const
inline QT_DEPRECATED const_iterator operator+(int j) const
{ const_iterator r = *this; if (j > 0) while (j--) ++r; else while (j++) --r; return r; }
inline const_iterator operator-(int j) const { return operator+(-j); }
inline const_iterator &operator+=(int j) { return *this = *this + j; }
inline const_iterator &operator-=(int j) { return *this = *this - j; }
friend inline const_iterator operator+(int j, const_iterator k) { return k + j; }
inline QT_DEPRECATED const_iterator operator-(int j) const { return operator+(-j); }
inline QT_DEPRECATED const_iterator &operator+=(int j) { return *this = *this + j; }
inline QT_DEPRECATED const_iterator &operator-=(int j) { return *this = *this - j; }
friend inline QT_DEPRECATED const_iterator operator+(int j, const_iterator k)
{
return k + j;
}
#endif
// ### Qt 5: not sure this is necessary anymore
#ifdef QT_STRICT_ITERATORS
@ -462,8 +481,14 @@ public:
inline key_iterator &operator++() { ++i; return *this; }
inline key_iterator operator++(int) { return key_iterator(i++);}
inline key_iterator &operator--() { --i; return *this; }
inline key_iterator operator--(int) { return key_iterator(i--); }
#if QT_DEPRECATED_SINCE(5, 15)
inline QT_DEPRECATED key_iterator &operator--()
{
--i;
return *this;
}
inline QT_DEPRECATED key_iterator operator--(int) { return key_iterator(i--); }
#endif
const_iterator base() const { return i; }
};
@ -587,12 +612,31 @@ Q_INLINE_TEMPLATE QHash<Key, T> &QHash<Key, T>::unite(const QHash &other)
if (d == &QHashData::shared_null) {
*this = other;
} else {
#if QT_DEPRECATED_SINCE(5, 15)
QHash copy(other);
const_iterator it = copy.constEnd();
while (it != copy.constBegin()) {
QT_WARNING_PUSH
QT_WARNING_DISABLE_DEPRECATED
--it;
QT_WARNING_POP
insertMulti(it.key(), it.value());
}
#else
QHash copy(other);
const_iterator it = copy.cbegin();
const const_iterator end = copy.cend();
while (it != end) {
const auto rangeStart = it++;
while (it != end && rangeStart.key() == it.key())
++it;
const qint64 last = std::distance(rangeStart, it) - 1;
for (qint64 i = last; i >= 0; --i) {
auto next = std::next(rangeStart, i);
insertMulti(next.key(), next.value());
}
}
#endif
}
return *this;
}
@ -1145,8 +1189,180 @@ Q_INLINE_TEMPLATE int QMultiHash<Key, T>::count(const Key &key, const T &value)
return n;
}
Q_DECLARE_ASSOCIATIVE_ITERATOR(Hash)
Q_DECLARE_MUTABLE_ASSOCIATIVE_ITERATOR(Hash)
template<class Key, class T>
class QHashIterator
{
typedef typename QHash<Key, T>::const_iterator const_iterator;
typedef const_iterator Item;
QHash<Key, T> c;
const_iterator i, n;
inline bool item_exists() const { return n != c.constEnd(); }
public:
inline QHashIterator(const QHash<Key, T> &container)
: c(container), i(c.constBegin()), n(c.constEnd())
{
}
inline QHashIterator &operator=(const QHash<Key, T> &container)
{
c = container;
i = c.constBegin();
n = c.constEnd();
return *this;
}
inline void toFront()
{
i = c.constBegin();
n = c.constEnd();
}
inline void toBack()
{
i = c.constEnd();
n = c.constEnd();
}
inline bool hasNext() const { return i != c.constEnd(); }
inline Item next()
{
n = i++;
return n;
}
inline Item peekNext() const { return i; }
inline const T &value() const
{
Q_ASSERT(item_exists());
return *n;
}
inline const Key &key() const
{
Q_ASSERT(item_exists());
return n.key();
}
inline bool findNext(const T &t)
{
while ((n = i) != c.constEnd())
if (*i++ == t)
return true;
return false;
}
#if QT_DEPRECATED_SINCE(5, 15)
inline QT_DEPRECATED bool hasPrevious() const { return i != c.constBegin(); }
inline QT_DEPRECATED Item previous()
{
n = --i;
return n;
}
inline QT_DEPRECATED Item peekPrevious() const
{
const_iterator p = i;
return --p;
}
inline bool QT_DEPRECATED findPrevious(const T &t)
{
while (i != c.constBegin())
if (*(n = --i) == t)
return true;
n = c.constEnd();
return false;
}
#endif
};
template<class Key, class T>
class QMutableHashIterator
{
typedef typename QHash<Key, T>::iterator iterator;
typedef typename QHash<Key, T>::const_iterator const_iterator;
typedef iterator Item;
QHash<Key, T> *c;
iterator i, n;
inline bool item_exists() const { return const_iterator(n) != c->constEnd(); }
public:
inline QMutableHashIterator(QHash<Key, T> &container) : c(&container)
{
i = c->begin();
n = c->end();
}
inline QMutableHashIterator &operator=(QHash<Key, T> &container)
{
c = &container;
i = c->begin();
n = c->end();
return *this;
}
inline void toFront()
{
i = c->begin();
n = c->end();
}
inline void toBack()
{
i = c->end();
n = c->end();
}
inline bool hasNext() const { return const_iterator(i) != c->constEnd(); }
inline Item next()
{
n = i++;
return n;
}
inline Item peekNext() const { return i; }
inline void remove()
{
if (const_iterator(n) != c->constEnd()) {
i = c->erase(n);
n = c->end();
}
}
inline void setValue(const T &t)
{
if (const_iterator(n) != c->constEnd())
*n = t;
}
inline T &value()
{
Q_ASSERT(item_exists());
return *n;
}
inline const T &value() const
{
Q_ASSERT(item_exists());
return *n;
}
inline const Key &key() const
{
Q_ASSERT(item_exists());
return n.key();
}
inline bool findNext(const T &t)
{
while (const_iterator(n = i) != c->constEnd())
if (*i++ == t)
return true;
return false;
}
#if QT_DEPRECATED_SINCE(5, 15)
inline QT_DEPRECATED bool hasPrevious() const { return const_iterator(i) != c->constBegin(); }
inline QT_DEPRECATED Item previous()
{
n = --i;
return n;
}
inline QT_DEPRECATED Item peekPrevious() const
{
iterator p = i;
return --p;
}
inline QT_DEPRECATED bool findPrevious(const T &t)
{
while (const_iterator(i) != c->constBegin())
if (*(n = --i) == t)
return true;
n = c->end();
return false;
}
#endif
};
template <class Key, class T>
uint qHash(const QHash<Key, T> &key, uint seed = 0)

2
src/xml/dom/qdom.cpp
View File

@ -2648,7 +2648,7 @@ QDomNodePrivate* QDomNamedNodeMapPrivate::item(int index) const
{
if (index >= length() || index < 0)
return nullptr;
return *(map.constBegin() + index);
return *std::next(map.cbegin(), index);
}
int QDomNamedNodeMapPrivate::length() const