const_iterator Struct
Struct const_iterator is declared in class QAssociativeIterable.The QAssociativeIterable::const_iterator allows iteration over a container in a QVariant. More...
This struct was introduced in Qt 5.2.
Public Functions
const_iterator(const const_iterator &other) | |
const_iterator & | operator=(const const_iterator &other) |
~const_iterator() | |
const QVariant | key() const |
const QVariant | value() const |
bool | operator!=(const const_iterator &other) const |
const QVariant | operator*() const |
const_iterator | operator+(int j) const |
const_iterator & | operator++() |
const_iterator | operator++(int) |
const_iterator & | operator+=(int j) |
const_iterator | operator-(int j) const |
const_iterator & | operator--() |
const_iterator | operator--(int) |
const_iterator & | operator-=(int j) |
bool | operator==(const const_iterator &other) const |
Detailed Description
A QAssociativeIterable::const_iterator can only be created by a QAssociativeIterable instance, and can be used in a way similar to other stl-style iterators.
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(); } }
See also QAssociativeIterable.
Member Function Documentation
const_iterator::const_iterator(const const_iterator &other)
Creates a copy of other.
const_iterator &const_iterator::operator=(const const_iterator &other)
Assigns other to this.
const_iterator::~const_iterator()
Destroys the QAssociativeIterable::const_iterator.
const QVariant const_iterator::key() const
Returns the current key, converted to a QVariant.
const QVariant const_iterator::value() const
Returns the current value, converted to a QVariant.
bool const_iterator::operator!=(const const_iterator &other) const
Returns true
if other points to a different item than this iterator; otherwise returns false
.
See also operator==().
const QVariant const_iterator::operator*() const
Returns the current value, converted to a QVariant.
const_iterator const_iterator::operator+(int j) const
Returns an iterator to the item at j positions forward from this iterator.
See also operator-() and operator+=().
const_iterator &const_iterator::operator++()
The prefix ++ operator (++it
) advances the iterator to the next item in the container and returns an iterator to the new current item.
Calling this function on QAssociativeIterable::end() leads to undefined results.
See also operator--().
const_iterator const_iterator::operator++(int)
This is an overloaded function.
The postfix ++ operator (it++
) advances the iterator to the next item in the container and returns an iterator to the previously current item.
const_iterator &const_iterator::operator+=(int j)
Advances the iterator by j items.
See also operator-=() and operator+().
const_iterator const_iterator::operator-(int j) const
Returns an iterator to the item at j positions backward from this iterator.
See also operator+() and operator-=().
const_iterator &const_iterator::operator--()
The prefix -- operator (--it
) makes the preceding item current and returns an iterator to the new current item.
Calling this function on QAssociativeIterable::begin() leads to undefined results.
See also operator++().
const_iterator const_iterator::operator--(int)
This is an overloaded function.
The postfix -- operator (it--
) makes the preceding item current and returns an iterator to the previously current item.
const_iterator &const_iterator::operator-=(int j)
Makes the iterator go back by j items.
See also operator+=() and operator-().
bool const_iterator::operator==(const const_iterator &other) const
Returns true
if other points to the same item as this iterator; otherwise returns false
.
See also operator!=().
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