QKeyValueIterator Class
template <typename Key, typename T, typename Iterator> class QKeyValueIteratorIterator over the key/value pairs of an associative container. More...
| Header: | #include <QKeyValueIterator> |
| qmake: | QT += core |
| Since: | Qt 5.10 |
This class was introduced in Qt 5.10.
Public Functions
| QKeyValueIterator(Iterator o) | |
| QKeyValueIterator() | |
| Iterator | base() const |
| std::pair<Key, T> | operator*() const |
| QKeyValueIterator<Key, T, Iterator> & | operator++() |
| QKeyValueIterator<Key, T, Iterator> | operator++(int) |
| QKeyValueIterator<Key, T, Iterator> & | operator--() |
| QKeyValueIterator<Key, T, Iterator> | operator--(int) |
| pointer | operator->() const |
Related Non-Members
| bool | operator!=(QKeyValueIterator<Key, T, Iterator> lhs, QKeyValueIterator<Key, T, Iterator> rhs) |
| bool | operator==(QKeyValueIterator<Key, T, Iterator> lhs, QKeyValueIterator<Key, T, Iterator> rhs) |
Detailed Description
The QKeyValueIterator class provides an STL-style iterator for returning key/value pairs from associative containers like QHash and QMap. It supports the same API as the STL associative containers, i.e. getting a key/value pair when iterating through the container.
This will allow for better interoperability between QMap, QHash and friends and STL-style algorithms.
Warning: Iterators on implicitly shared containers do not work exactly like STL-iterators. You should avoid copying a container while iterators are active on that container. For more information, read Implicit sharing iterator problem.
Member Function Documentation
QKeyValueIterator::QKeyValueIterator(Iterator o)
Constructs a QKeyValueIterator on top of o.
QKeyValueIterator::QKeyValueIterator()
Constructs a default QKeyValueIterator.
Iterator QKeyValueIterator::base() const
Returns the underlying iterator this QKeyValueIterator is based on.
std::pair<Key, T> QKeyValueIterator::operator*() const
Returns the current entry as a pair.
QKeyValueIterator<Key, T, Iterator> &QKeyValueIterator::operator++()
The prefix ++ operator (++i) advances the iterator to the next item in the container and returns the iterator.
Note: Advancing the iterator past its container's end() constitutes undefined behavior.
See also operator--().
QKeyValueIterator<Key, T, Iterator> QKeyValueIterator::operator++(int)
This is an overloaded function.
The postfix ++ operator (i++) advances the iterator to the next item in the container and returns the iterator's prior value.
Note: Advancing the iterator past its container's end() constitutes undefined behavior.
QKeyValueIterator<Key, T, Iterator> &QKeyValueIterator::operator--()
The prefix -- operator (--i) backs the iterator up to the previous item in the container and returns the iterator.
Note: Backing up an iterator to before its container's begin() constitutes undefined behavior.
See also operator++().
QKeyValueIterator<Key, T, Iterator> QKeyValueIterator::operator--(int)
This is an overloaded function.
The postfix -- operator (i--) backs the iterator up to the previous item in the container and returns the iterator's prior value.
Note: Backing up an iterator to before its container's begin() constitutes undefined behavior.
pointer QKeyValueIterator::operator->() const
Returns the current entry as a pointer-like object to the pair.
This function was introduced in Qt 5.15.
See also operator*().
Related Non-Members
bool operator!=(QKeyValueIterator<Key, T, Iterator> lhs, QKeyValueIterator<Key, T, Iterator> rhs)
Returns true if rhs points to a different item than lhs otherwise returns false.
See also operator==().
bool operator==(QKeyValueIterator<Key, T, Iterator> lhs, QKeyValueIterator<Key, T, Iterator> rhs)
Returns true if rhs points to the same item as lhs otherwise returns false.
See also operator!=().