The QMultiMap class is a convenience QMap subclass that provides multi-valued maps. More...

#include <qcontainerfwd.h>

Inheritance diagram for QMultiMap< Key, T >:

Public Functions
QMap< Key, T >::const_iterator	constFind (const Key &key, const T &value) const
	Returns an iterator pointing to the item with key key and the value value in the map. More...

bool	contains (const Key &key, const T &value) const
	Returns true if the map contains an item with key key and value value; otherwise returns false. More...

int	count (const Key &key, const T &value) const
	Returns the number of items with key key and value value. More...

QMap< Key, T >::iterator	find (const Key &key, const T &value)
	Returns an iterator pointing to the item with key key and value value in the map. More...

QMap< Key, T >::const_iterator	find (const Key &key, const T &value) const
	Returns a const iterator pointing to the item with the given key and value in the map. More...

QMap< Key, T >::iterator	insert (const Key &key, const T &value)
	Inserts a new item with the key key and a value of value. More...

QMultiMap	operator+ (const QMultiMap &other) const
	Returns a map that contains all the items in this map in addition to all the items in other. More...

QMultiMap &	operator+= (const QMultiMap &other)
	Inserts all the items in the other map into this map and returns a reference to this map. More...

	QMultiMap ()
	Constructs an empty map. More...

	QMultiMap (const QMap< Key, T > &other)
	Constructs a copy of other (which can be a QMap or a QMultiMap). More...

int	remove (const Key &key, const T &value)
	Removes all the items that have the key key and the value value from the map. More...

QMap< Key, T >::iterator	replace (const Key &key, const T &value)
	Inserts a new item with the key key and a value of value. More...

void	swap (QMultiMap< Key, T > &other)
	Swaps map other with this map. More...

Public Functions inherited from QMap< Key, T >
iterator	begin ()
	Returns an STL-style iterator pointing to the first item in the map. More...

const_iterator	begin () const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...

void	clear ()
	Removes all items from the map. More...

const_iterator	constBegin () const
	Returns a const STL-style iterator pointing to the first item in the map. More...

const_iterator	constEnd () const
	Returns a const STL-style iterator pointing to the imaginary item after the last item in the map. More...

const_iterator	constFind (const Key &key) const
	Returns an const iterator pointing to the item with key key in the map. More...

bool	contains (const Key &key) const
	Returns true if the map contains an item with key key; otherwise returns false. More...

int	count (const Key &key) const
	Returns the number of items associated with key key. More...

int	count () const
	Same as size(). More...

void	detach ()
	Detaches this map from any other maps with which it may share data. More...

bool	empty () const
	This function is provided for STL compatibility. More...

iterator	end ()
	Returns an STL-style iterator pointing to the imaginary item after the last item in the map. More...

const_iterator	end () const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...

iterator	erase (iterator it)
	Removes the (key, value) pair pointed to by the iterator pos from the map, and returns an iterator to the next item in the map. More...

iterator	find (const Key &key)
	Returns an iterator pointing to the item with key key in the map. More...

const_iterator	find (const Key &key) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...

iterator	insert (const Key &key, const T &value)
	Inserts a new item with the key key and a value of value. More...

iterator	insertMulti (const Key &key, const T &value)
	Inserts a new item with the key key and a value of value. More...

bool	isDetached () const
	Returns true if the map's internal data isn't shared with any other map object; otherwise returns false. More...

bool	isEmpty () const
	Returns true if the map contains no items; otherwise returns false. More...

bool	isSharedWith (const QMap< Key, T > &other) const

const Key	key (const T &value) const
	Returns the first key with value value. More...

const Key	key (const T &value, const Key &defaultKey) const
	Returns the first key with value value, or defaultKey if the map contains no item with value value. More...

QList< Key >	keys () const
	Returns a list containing all the keys in the map in ascending order. More...

QList< Key >	keys (const T &value) const
	Returns a list containing all the keys associated with value value in ascending order. More...

iterator	lowerBound (const Key &key)
	Returns an iterator pointing to the first item with key key in the map. More...

const_iterator	lowerBound (const Key &key) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...

bool	operator!= (const QMap< Key, T > &other) const
	Returns true if other is not equal to this map; otherwise returns false. More...

QMap< Key, T > &	operator= (const QMap< Key, T > &other)
	Assigns other to this map and returns a reference to this map. More...

bool	operator== (const QMap< Key, T > &other) const
	Returns true if other is equal to this map; otherwise returns false. More...

T &	operator[] (const Key &key)
	Returns the value associated with the key key as a modifiable reference. More...

const T	operator[] (const Key &key) const
	Same as value(). More...

	QMap ()
	Constructs an empty map. More...

	QMap (const QMap< Key, T > &other)
	Constructs a copy of other. More...

	QMap (const typename std::map< Key, T > &other)

int	remove (const Key &key)
	Removes all the items that have the key key from the map. More...

void	setInsertInOrder (bool ordered)

void	setSharable (bool sharable)

int	size () const
	Returns the number of (key, value) pairs in the map. More...

void	swap (QMap< Key, T > &other)
	Swaps map other with this map. More...

T	take (const Key &key)
	Removes the item with the key key from the map and returns the value associated with it. More...

std::map< Key, T >	toStdMap () const
	Returns an STL map equivalent to this QMap. More...

QList< Key >	uniqueKeys () const
	Returns a list containing all the keys in the map in ascending order. More...

QMap< Key, T > &	unite (const QMap< Key, T > &other)
	Inserts all the items in the other map into this map. More...

iterator	upperBound (const Key &key)
	Returns an iterator pointing to the item that immediately follows the last item with key key in the map. More...

const_iterator	upperBound (const Key &key) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...

const T	value (const Key &key) const
	Returns the value associated with the key key. More...

const T	value (const Key &key, const T &defaultValue) const
	If the map contains no item with key key, the function returns defaultValue. More...

QList< T >	values () const
	Returns a list containing all the values in the map, in ascending order of their keys. More...

QList< T >	values (const Key &key) const
	Returns a list containing all the values associated with key key, from the most recently inserted to the least recently inserted one. More...

	~QMap ()
	Destroys the map. More...

Private Functions
T &	operator[] (const Key &key)

const T	operator[] (const Key &key) const

Additional Inherited Members
Public Types inherited from QMap< Key, T >
typedef const_iterator	ConstIterator
	Qt-style synonym for QMap::const_iterator. More...

typedef qptrdiff	difference_type
	Typedef for ptrdiff_t. More...

typedef iterator	Iterator
	Qt-style synonym for QMap::iterator. More...

typedef Key	key_type
	Typedef for Key. More...

typedef T	mapped_type
	Typedef for T. More...

typedef int	size_type
	Typedef for int. More...

Related Functions inherited from QMap< Key, T >
QDataStream &	operator<< (QDataStream &out, const QMap< Key, T > &map)
	Writes the map map to stream out. More...

QDataStream &	operator>> (QDataStream &in, QMap< Key, T > &map)
	Reads a map from stream in into map. More...

Detailed Description

template<class Key, class T>
class QMultiMap< Key, T >

The QMultiMap class is a convenience QMap subclass that provides multi-valued maps.

Note: This class or function is reentrant.

QMultiMap<Key, T> is one of Qt's generic container classes. It inherits QMap and extends it with a few convenience functions that make it more suitable than QMap for storing multi-valued maps. A multi-valued map is a map that allows multiple values with the same key; QMap normally doesn't allow that, unless you call QMap::insertMulti().

Because QMultiMap inherits QMap, all of QMap's functionality also applies to QMultiMap. For example, you can use isEmpty() to test whether the map is empty, and you can traverse a QMultiMap using QMap's iterator classes (for example, QMapIterator). But in addition, it provides an insert() function that corresponds to QMap::insertMulti(), and a replace() function that corresponds to QMap::insert(). It also provides convenient operator+() and operator+=().

Example:

QMultiMap<QString, int> map1, map2, map3;
map1.insert("plenty", 100);
map1.insert("plenty", 2000);
// map1.size() == 2
map2.insert("plenty", 5000);
// map2.size() == 1
map3 = map1 + map2;
// map3.size() == 3

Unlike QMap, QMultiMap provides no operator[]. Use value() or replace() if you want to access the most recently inserted item with a certain key.

If you want to retrieve all the values for a single key, you can use values(const Key &key), which returns a QList<T>:

QList<int> values = map.values("plenty");
for (int i = 0; i < values.size(); ++i)
    cout << values.at(i) << endl;

The items that share the same key are available from most recently to least recently inserted.

If you prefer the STL-style iterators, you can call find() to get the iterator for the first item with a key and iterate from there:

QMultiMap<QString, int>::iterator i = map.find("plenty");
while (i != map.end() && i.key() == "plenty") {
    cout << i.value() << endl;
    ++i;
}

QMultiMap's key and value data types must be assignable data types. This covers most data types you are likely to encounter, but the compiler won't let you, for example, store a QWidget as a value; instead, store a QWidget *. In addition, QMultiMap's key type must provide operator<(). See the QMap documentation for details.

See also: QMap, QMapIterator, QMutableMapIterator, QMultiHash

Definition at line 59 of file qcontainerfwd.h.

Constructors and Destructors

◆ QMultiMap() [1/2]

template<class Key, class T>

QMultiMap< Key, T >::QMultiMap ( )

inline

Constructs an empty map.

Definition at line 976 of file qmap.h.

976 {}

◆ QMultiMap() [2/2]

template<class Key, class T>

QMultiMap< Key, T >::QMultiMap ( const QMap< Key, T > & other )

inline

Constructs a copy of other (which can be a QMap or a QMultiMap).

See also: operator=()

Definition at line 977 of file qmap.h.

977 : QMap<Key, T>(other) {}

QMap

The QMap class is a template class that provides a skip-list-based dictionary.

Definition: qdatastream.h:67

Functions

◆ constFind()

template<class Key, class T>

typename QMap< Key, T >::const_iterator QMultiMap< Key, T >::constFind	(	const Key &	key,
		const T &	value
	)		const

inline

Returns an iterator pointing to the item with key key and the value value in the map.

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 4.3

If the map contains no such item, the function returns constEnd().

See also: QMap::constFind(); QMap::constFind()

Definition at line 1040 of file qmap.h.

1041 { return find(key, value); }

QMap::key

const Key key(const T &value) const

Returns the first key with value value.

Definition: qmap.h:844

QMultiMap::find

QMap< Key, T >::iterator find(const Key &key, const T &value)

Returns an iterator pointing to the item with key key and value value in the map. ...

Definition: qmap.h:1020

QMap::value

const T value(const Key &key) const

Returns the value associated with the key key.

Definition: qmap.h:499

◆ contains()

template<class Key, class T>

Q_INLINE_TEMPLATE bool QMultiMap< Key, T >::contains	(	const Key &	key,
		const T &	value
	)		const

Returns true if the map contains an item with key key and value value; otherwise returns false.

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 4.3

See also: QMap::contains(); QMap::contains()

Definition at line 1048 of file qmap.h.

Referenced by QGraphicsScenePrivate::filterEvent(), and QGraphicsScenePrivate::removeSceneEventFilter().

 {
     return constFind(key, value) != QMap<Key, T>::constEnd();
 }

◆ count()

template<class Key, class T>

Q_INLINE_TEMPLATE int QMultiMap< Key, T >::count	(	const Key &	key,
		const T &	value
	)		const

Returns the number of items with key key and value value.

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 4.3

See also: QMap::count(); QMap::count()

Definition at line 1071 of file qmap.h.

Referenced by QNetworkDiskCache::expire().

 {
     int n = 0;
     typename QMap<Key, T>::const_iterator i(constFind(key));
     typename QMap<Key, T>::const_iterator end(QMap<Key, T>::constEnd());
     while (i != end && !qMapLessThanKey<Key>(key, i.key())) {
         if (i.value() == value)
             ++n;
         ++i;
     }
     return n;
 }

◆ find() [1/2]

template<class Key, class T>

typename QMap< Key, T >::iterator QMultiMap< Key, T >::find	(	const Key &	key,
		const T &	value
	)

inline

Returns an iterator pointing to the item with key key and value value in the map.

Since: 4.3

If the map contains no such item, the function returns end().

If the map contains multiple items with key key, this function returns an iterator that points to the most recently inserted value.

See also: QMap::find()

Definition at line 1020 of file qmap.h.

                                                                        {
         typename QMap<Key, T>::iterator i(find(key));
         typename QMap<Key, T>::iterator end(this->end());
         while (i != end && !qMapLessThanKey<Key>(key, i.key())) {
             if (i.value() == value)
                 return i;
             ++i;
         }
         return end;
     }

◆ find() [2/2]

template<class Key, class T>

typename QMap< Key, T >::const_iterator QMultiMap< Key, T >::find	(	const Key &	key,
		const T &	value
	)		const

inline

Returns a const iterator pointing to the item with the given key and value in the map.

Since: 4.3 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

If the map contains no such item, the function returns end().

If the map contains multiple items with the specified key, this function returns a const iterator that points to the most recently inserted value.

See also: QMap::find()

Definition at line 1030 of file qmap.h.

                                                                                    {
         typename QMap<Key, T>::const_iterator i(constFind(key));
         typename QMap<Key, T>::const_iterator end(QMap<Key, T>::constEnd());
         while (i != end && !qMapLessThanKey<Key>(key, i.key())) {
             if (i.value() == value)
                 return i;
             ++i;
         }
         return end;
     }

◆ insert()

template<class Key, class T>

QMultiMap::iterator QMultiMap< Key, T >::insert	(	const Key &	key,
		const T &	value
	)

inline

Inserts a new item with the key key and a value of value.

If there is already an item with the same key in the map, this function will simply create a new one. (This behavior is different from replace(), which overwrites the value of an existing item.)

See also: replace()

Definition at line 982 of file qmap.h.

Referenced by QSslCertificate::alternateSubjectNames(), QNetworkDiskCache::expire(), QGestureManager::filterEvent(), QGraphicsScenePrivate::installSceneEventFilter(), and QDBusXmlParser::interfaces().

983 { return QMap<Key, T>::insertMulti(key, value); }

QMap::key

const Key key(const T &value) const

Returns the first key with value value.

Definition: qmap.h:844

QMap::insertMulti

iterator insertMulti(const Key &key, const T &value)

Inserts a new item with the key key and a value of value.

Definition: qmap.h:595

QMap::value

const T value(const Key &key) const

Returns the value associated with the key key.

Definition: qmap.h:499

◆ operator+()

template<class Key, class T>

QMultiMap QMultiMap< Key, T >::operator+ ( const QMultiMap< Key, T > & other ) const

inline

Returns a map that contains all the items in this map in addition to all the items in other.

If a key is common to both maps, the resulting map will contain the key multiple times.

See also: operator+=()

Definition at line 987 of file qmap.h.

988 { QMultiMap result = *this; result += other; return result; }

QMultiMap

The QMultiMap class is a convenience QMap subclass that provides multi-valued maps.

Definition: qcontainerfwd.h:59

◆ operator+=()

template<class Key, class T>

QMultiMap & QMultiMap< Key, T >::operator+= ( const QMultiMap< Key, T > & other )

inline

Inserts all the items in the other map into this map and returns a reference to this map.

See also: insert(), operator+()

Definition at line 985 of file qmap.h.

986 { this->unite(other); return *this; }

QMap::unite

QMap< Key, T > & unite(const QMap< Key, T > &other)

Inserts all the items in the other map into this map.

Definition: qmap.h:625

◆ operator[]() [1/2]

template<class Key, class T>

T& QMultiMap< Key, T >::operator[] ( const Key & key )

private

◆ operator[]() [2/2]

template<class Key, class T>

const T QMultiMap< Key, T >::operator[] ( const Key & key ) const

private

◆ remove()

template<class Key, class T>

Q_INLINE_TEMPLATE int QMultiMap< Key, T >::remove	(	const Key &	key,
		const T &	value
	)

Removes all the items that have the key key and the value value from the map.

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 4.3

Returns the number of items removed.

See also: QMap::remove(); QMap::remove()

Definition at line 1054 of file qmap.h.

 {
     int n = 0;
     typename QMap<Key, T>::iterator i(find(key));
     typename QMap<Key, T>::iterator end(QMap<Key, T>::end());
     while (i != end && !qMapLessThanKey<Key>(key, i.key())) {
         if (i.value() == value) {
             i = this->erase(i);
             ++n;
         } else {
             ++i;
         }
     }
     return n;
 }

◆ replace()

template<class Key, class T>

QMultiMap::iterator QMultiMap< Key, T >::replace	(	const Key &	key,
		const T &	value
	)

inline

Inserts a new item with the key key and a value of value.

If there is already an item with the key key, that item's value is replaced with value.

If there are multiple items with the key key, the most recently inserted item's value is replaced with value.

See also: insert()

Definition at line 980 of file qmap.h.

981 { return QMap<Key, T>::insert(key, value); }

QMap::key

const Key key(const T &value) const

Returns the first key with value value.

Definition: qmap.h:844

QMap::value

const T value(const Key &key) const

Returns the value associated with the key key.

Definition: qmap.h:499

QMap::insert

iterator insert(const Key &key, const T &value)

Inserts a new item with the key key and a value of value.

Definition: qmap.h:559

◆ swap()

template<class Key, class T>

void QMultiMap< Key, T >::swap ( QMultiMap< Key, T > & other )

inline

Swaps map other with this map.

Since: 4.8

This operation is very fast and never fails.

Definition at line 978 of file qmap.h.

978 { QMap<Key, T>::swap(other); }

QMap::swap

void swap(QMap< Key, T > &other)

Swaps map other with this map.

Definition: qmap.h:192

The documentation for this class was generated from the following files:

/src/corelib/tools/qcontainerfwd.h
/src/corelib/tools/qmap.h
/src/corelib/tools/qmap.cpp

Public Functions

Private Functions

Additional Inherited Members

Detailed Description

template<class Key, class T> class QMultiMap< Key, T >

Constructors and Destructors

◆ QMultiMap() [1/2]

◆ QMultiMap() [2/2]

Functions

◆ constFind()

◆ contains()

◆ count()

◆ find() [1/2]

◆ find() [2/2]

◆ insert()

◆ operator+()

◆ operator+=()

◆ operator[]() [1/2]

◆ operator[]() [2/2]

◆ remove()

◆ replace()

◆ swap()

template<class Key, class T>
class QMultiMap< Key, T >