QAssociativeIterable Class Reference

The QAssociativeIterable class is an iterable interface for an associative container in a QVariant. More...

#include <qassociativeiterable.h>

Inheritance diagram for QAssociativeIterable:

Collaboration diagram for QAssociativeIterable:

Public Types
using	iterator = QTaggedIterator<QAssociativeIterator, void>
using	const_iterator = QTaggedIterator<QAssociativeConstIterator, void>
using	RandomAccessIterator = QTaggedIterator<iterator, std::random_access_iterator_tag>
	Exposes an iterator using std::random_access_iterator_tag.
using	BidirectionalIterator = QTaggedIterator<iterator, std::bidirectional_iterator_tag>
	Exposes an iterator using std::bidirectional_iterator_tag.
using	ForwardIterator = QTaggedIterator<iterator, std::forward_iterator_tag>
	Exposes an iterator using std::forward_iterator_tag.
using	InputIterator = QTaggedIterator<iterator, std::input_iterator_tag>
	Exposes an iterator using std::input_iterator_tag.
using	RandomAccessConstIterator = QTaggedIterator<const_iterator, std::random_access_iterator_tag>
	Exposes a const_iterator using std::random_access_iterator_tag.
using	BidirectionalConstIterator = QTaggedIterator<const_iterator, std::bidirectional_iterator_tag>
	Exposes a const_iterator using std::bidirectional_iterator_tag.
using	ForwardConstIterator = QTaggedIterator<const_iterator, std::forward_iterator_tag>
	Exposes a const_iterator using std::forward_iterator_tag.
using	InputConstIterator = QTaggedIterator<const_iterator, std::input_iterator_tag>
	Exposes a const_iterator using std::input_iterator_tag.

Public Member Functions
template<class T >
	QAssociativeIterable (const T *p)
template<class T >
	QAssociativeIterable (T *p)
	QAssociativeIterable ()
template<typename Pointer >
	QAssociativeIterable (const QMetaAssociation &metaAssociation, Pointer iterable)
	QAssociativeIterable (const QMetaAssociation &metaAssociation, const QMetaType &metaType, void *iterable)
	QAssociativeIterable (const QMetaAssociation &metaAssociation, const QMetaType &metaType, const void *iterable)
	QAssociativeIterable (QIterable< QMetaAssociation > &&other)
QAssociativeIterable &	operator= (QIterable< QMetaAssociation > &&other)
const_iterator	begin () const
const_iterator	end () const
const_iterator	constBegin () const
const_iterator	constEnd () const
iterator	mutableBegin ()
iterator	mutableEnd ()
const_iterator	find (const QVariant &key) const
	Retrieves a const_iterator pointing to the element at the given key, or the end of the container if that key does not exist.
const_iterator	constFind (const QVariant &key) const
iterator	mutableFind (const QVariant &key)
	Retrieves an iterator pointing to the element at the given key, or the end of the container if that key does not exist.
bool	containsKey (const QVariant &key)
	Returns true if the container has an entry with the given key, or false otherwise.
void	insertKey (const QVariant &key)
	Inserts a new entry with the given key, or resets the mapped value of any existing entry with the given key to the default constructed mapped value.
void	removeKey (const QVariant &key)
	Removes the entry with the given key from the container.
QVariant	value (const QVariant &key) const
	Retrieves the mapped value at the given key, or a default-constructed QVariant of the mapped type, if the key does not exist.
void	setValue (const QVariant &key, const QVariant &mapped)
	Sets the mapped value associated with key to mapped, if possible.
Public Member Functions inherited from QIterable< QMetaAssociation >
	QIterable (const QMetaAssociation &metaContainer, const T *p)
	QIterable (const QMetaAssociation &metaContainer, T *p)
	QIterable (const QMetaAssociation &metaContainer, Pointer iterable)
	QIterable (const QMetaAssociation &metaContainer, qsizetype alignment, const void *p)
	QIterable (const QMetaAssociation &metaContainer, qsizetype alignment, void *p)
bool	canInputIterate () const
	Returns whether the container has an input iterator.
bool	canForwardIterate () const
	Returns whether it is possible to iterate over the container in forward direction.
bool	canReverseIterate () const
	Returns whether it is possible to iterate over the container in reverse.
bool	canRandomAccessIterate () const
	Returns whether it is possible to efficiently skip over multiple values using and iterator.
const void *	constIterable () const
void *	mutableIterable ()
QConstIterator< QMetaAssociation >	constBegin () const
	Returns a QConstIterator for the beginning of the container.
QConstIterator< QMetaAssociation >	constEnd () const
	Returns a Qterable::QConstIterator for the end of the container.
QIterator< QMetaAssociation >	mutableBegin ()
	Returns a QIterator for the beginning of the container.
QIterator< QMetaAssociation >	mutableEnd ()
	Returns a QSequentialIterable::iterator for the end of the container.
qsizetype	size () const
	Returns the number of values in the container.
QMetaAssociation	metaContainer () const

Additional Inherited Members
Protected Attributes inherited from QIterable< QMetaAssociation >
uint	m_revision
QtPrivate::QConstPreservingPointer< void, quint16 >	m_iterable
QMetaAssociation	m_metaContainer

Detailed Description

The QAssociativeIterable class is an iterable interface for an associative container in a QVariant.

Since

5.2 \inmodule QtCore

This class allows several methods of accessing the elements of an associative container held within a QVariant. An instance of QAssociativeIterable can be extracted from a QVariant if it can be converted to a QVariantHash or QVariantMap or if a custom mutable view has been registered.

 
QHash<int, QString> mapping;
mapping.insert(7, "Seven");
mapping.insert(11, "Eleven");
mapping.insert(42, "Forty-two");
 
QVariant variant = QVariant::fromValue(mapping);
if (variant.canConvert<QVariantHash>()) {
    QAssociativeIterable iterable = variant.value<QAssociativeIterable>();
    // Can use foreach over the values:
    foreach (const QVariant &v, iterable) {
        qDebug() << v;
    }
    // Can use C++11 range-for over the values:
    for (const QVariant &v : iterable) {
        qDebug() << v;
    }
    // Can use iterators:
    QAssociativeIterable::const_iterator it = iterable.begin();
    const QAssociativeIterable::const_iterator end = iterable.end();
    for ( ; it != end; ++it) {
        qDebug() << *it; // The current value
        qDebug() << it.key();
        qDebug() << it.value();
    }
}
 

The container itself is not copied before iterating over it.

See also

QVariant

Definition at line 50 of file qassociativeiterable.h.

Member Typedef Documentation

BidirectionalConstIterator

QAssociativeIterable::BidirectionalConstIterator = QTaggedIterator<const_iterator, std::bidirectional_iterator_tag>

Exposes a const_iterator using std::bidirectional_iterator_tag.

Definition at line 62 of file qassociativeiterable.h.

BidirectionalIterator

QAssociativeIterable::BidirectionalIterator = QTaggedIterator<iterator, std::bidirectional_iterator_tag>

Exposes an iterator using std::bidirectional_iterator_tag.

Definition at line 57 of file qassociativeiterable.h.

const_iterator

using QAssociativeIterable::const_iterator = QTaggedIterator<QAssociativeConstIterator, void>

Definition at line 54 of file qassociativeiterable.h.

ForwardConstIterator

QAssociativeIterable::ForwardConstIterator = QTaggedIterator<const_iterator, std::forward_iterator_tag>

Exposes a const_iterator using std::forward_iterator_tag.

Definition at line 63 of file qassociativeiterable.h.

ForwardIterator

QAssociativeIterable::ForwardIterator = QTaggedIterator<iterator, std::forward_iterator_tag>

Exposes an iterator using std::forward_iterator_tag.

Definition at line 58 of file qassociativeiterable.h.

InputConstIterator

QAssociativeIterable::InputConstIterator = QTaggedIterator<const_iterator, std::input_iterator_tag>

Exposes a const_iterator using std::input_iterator_tag.

Definition at line 64 of file qassociativeiterable.h.

InputIterator

QAssociativeIterable::InputIterator = QTaggedIterator<iterator, std::input_iterator_tag>

Exposes an iterator using std::input_iterator_tag.

Definition at line 59 of file qassociativeiterable.h.

iterator

using QAssociativeIterable::iterator = QTaggedIterator<QAssociativeIterator, void>

Definition at line 53 of file qassociativeiterable.h.

RandomAccessConstIterator

QAssociativeIterable::RandomAccessConstIterator = QTaggedIterator<const_iterator, std::random_access_iterator_tag>

Exposes a const_iterator using std::random_access_iterator_tag.

Definition at line 61 of file qassociativeiterable.h.

RandomAccessIterator

QAssociativeIterable::RandomAccessIterator = QTaggedIterator<iterator, std::random_access_iterator_tag>

Exposes an iterator using std::random_access_iterator_tag.

Definition at line 56 of file qassociativeiterable.h.

Constructor & Destructor Documentation

QAssociativeIterable() [1/7]

template<class T >

QAssociativeIterable::QAssociativeIterable ( const T * p )

inline

Definition at line 67 of file qassociativeiterable.h.

QAssociativeIterable() [2/7]

template<class T >

QAssociativeIterable::QAssociativeIterable ( T * p )

inline

Definition at line 73 of file qassociativeiterable.h.

QAssociativeIterable() [3/7]

QAssociativeIterable::QAssociativeIterable ( )

inline

Definition at line 78 of file qassociativeiterable.h.

QAssociativeIterable() [4/7]

template<typename Pointer >

QAssociativeIterable::QAssociativeIterable ( const QMetaAssociation & metaAssociation, Pointer iterable )

inline

Definition at line 84 of file qassociativeiterable.h.

QAssociativeIterable() [5/7]

QAssociativeIterable::QAssociativeIterable ( const QMetaAssociation & metaAssociation, const QMetaType & metaType, void * iterable )

inline

Definition at line 90 of file qassociativeiterable.h.

QAssociativeIterable() [6/7]

QAssociativeIterable::QAssociativeIterable ( const QMetaAssociation & metaAssociation, const QMetaType & metaType, const void * iterable )

inline

Definition at line 97 of file qassociativeiterable.h.

QAssociativeIterable() [7/7]

QAssociativeIterable::QAssociativeIterable ( QIterable< QMetaAssociation > && other )

inline

Definition at line 103 of file qassociativeiterable.h.

Member Function Documentation

begin()

const_iterator QAssociativeIterable::begin ( ) const

inline

Definition at line 111 of file qassociativeiterable.h.

constBegin()

const_iterator QAssociativeIterable::constBegin ( ) const

inline

Definition at line 114 of file qassociativeiterable.h.

References QIterable< Container >::constBegin().

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constEnd()

const_iterator QAssociativeIterable::constEnd ( ) const

inline

Definition at line 115 of file qassociativeiterable.h.

References QIterable< Container >::constEnd().

Referenced by find().

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constFind()

const_iterator QAssociativeIterable::constFind ( const QVariant & key ) const

inline

Definition at line 121 of file qassociativeiterable.h.

containsKey()

bool QAssociativeIterable::containsKey

(

const QVariant &

key

)

Returns true if the container has an entry with the given key, or false otherwise.

If the key isn't convertible to the expected type, false is returned.

Definition at line 187 of file qassociativeiterable.cpp.

References QIterable< QMetaAssociation >::constIterable(), QMetaAssociation::containsKey(), QMetaAssociation::keyMetaType(), and QIterable< QMetaAssociation >::metaContainer().

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end()

const_iterator QAssociativeIterable::end ( ) const

inline

Definition at line 112 of file qassociativeiterable.h.

find()

QAssociativeIterable::const_iterator QAssociativeIterable::find

(

const QVariant &

key

)

const

Retrieves a const_iterator pointing to the element at the given key, or the end of the container if that key does not exist.

If the key isn't convertible to the expected type, the end of the container is returned.

Definition at line 157 of file qassociativeiterable.cpp.

References constEnd(), QIterable< QMetaAssociation >::constIterable(), QMetaAssociation::createConstIteratorAtKey(), QMetaAssociation::keyMetaType(), and QIterable< QMetaAssociation >::metaContainer().

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insertKey()

void QAssociativeIterable::insertKey

(

const QVariant &

key

)

Inserts a new entry with the given key, or resets the mapped value of any existing entry with the given key to the default constructed mapped value.

The key is coerced to the expected type: If it isn't convertible, a default value is inserted.

Definition at line 202 of file qassociativeiterable.cpp.

References QMetaAssociation::insertKey(), QMetaAssociation::keyMetaType(), QIterable< QMetaAssociation >::metaContainer(), and QIterable< QMetaAssociation >::mutableIterable().

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mutableBegin()

iterator QAssociativeIterable::mutableBegin ( )

inline

Definition at line 117 of file qassociativeiterable.h.

References QIterable< Container >::mutableBegin().

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mutableEnd()

iterator QAssociativeIterable::mutableEnd ( )

inline

Definition at line 118 of file qassociativeiterable.h.

References QIterable< Container >::mutableEnd().

Referenced by mutableFind().

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mutableFind()

QAssociativeIterable::iterator QAssociativeIterable::mutableFind

(

const QVariant &

key

)

Retrieves an iterator pointing to the element at the given key, or the end of the container if that key does not exist.

If the key isn't convertible to the expected type, the end of the container is returned.

Definition at line 173 of file qassociativeiterable.cpp.

References QMetaAssociation::createIteratorAtKey(), QMetaAssociation::keyMetaType(), QIterable< QMetaAssociation >::metaContainer(), mutableEnd(), and QIterable< QMetaAssociation >::mutableIterable().

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operator=()

QAssociativeIterable & QAssociativeIterable::operator= ( QIterable< QMetaAssociation > && other )

inline

Definition at line 105 of file qassociativeiterable.h.

References other().

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removeKey()

void QAssociativeIterable::removeKey

(

const QVariant &

key

)

Removes the entry with the given key from the container.

The key is coerced to the expected type: If it isn't convertible, the default value is removed.

Definition at line 214 of file qassociativeiterable.cpp.

References QMetaAssociation::keyMetaType(), QIterable< QMetaAssociation >::metaContainer(), QIterable< QMetaAssociation >::mutableIterable(), and QMetaAssociation::removeKey().

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setValue()

void QAssociativeIterable::setValue	(	const QVariant &	key,
		const QVariant &	mapped )

Sets the mapped value associated with key to mapped, if possible.

Inserts a new entry if none exists yet, for the given key. If the key is not convertible to the key type, the value for the default-constructed key type is overwritten.

Definition at line 253 of file qassociativeiterable.cpp.

References QMetaAssociation::keyMetaType(), QMetaAssociation::mappedMetaType(), QIterable< QMetaAssociation >::metaContainer(), QIterable< QMetaAssociation >::mutableIterable(), and QMetaAssociation::setMappedAtKey().

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value()

QVariant QAssociativeIterable::value

(

const QVariant &

key

)

const

Retrieves the mapped value at the given key, or a default-constructed QVariant of the mapped type, if the key does not exist.

If the key is not convertible to the key type, the mapped value associated with the default-constructed key is returned.

Definition at line 228 of file qassociativeiterable.cpp.

References QtPrivate::QVariantTypeCoercer::coerce(), QIterable< QMetaAssociation >::constIterable(), QMetaAssociation::keyMetaType(), QMetaAssociation::mappedAtKey(), QMetaAssociation::mappedMetaType(), and QIterable< QMetaAssociation >::metaContainer().

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

• qtbase/src/corelib/kernel/qassociativeiterable.h (05fc3aef53348fb58be6308076e000825b704e58)
• qtbase/src/corelib/kernel/qassociativeiterable.cpp (05fc3aef53348fb58be6308076e000825b704e58)