Struct qt_core::q_list_of_int::Iterator
source · #[repr(C)]pub struct Iterator { /* private fields */ }
Expand description
The QList::iterator class provides an STL-style non-const iterator for QList and QQueue.
C++ class: QList<int>::iterator
.
The QList::iterator class provides an STL-style non-const iterator for QList and QQueue.
QList features both STL-style iterators and Java-style iterators. The STL-style iterators are more low-level and more cumbersome to use; on the other hand, they are slightly faster and, for developers who already know STL, have the advantage of familiarity.
QList<T>::iterator allows you to iterate over a QList<T> (or QQueue<T>) and to modify the list item associated with the iterator. If you want to iterate over a const QList, use QList::const_iterator instead. It is generally good practice to use QList::const_iterator on a non-const QList as well, unless you need to change the QList through the iterator. Const iterators are slightly faster, and can improve code readability.
The default QList::iterator constructor creates an uninitialized iterator. You must initialize it using a QList function like QList::begin(), QList::end(), or QList::insert() before you can start iterating. Here's a typical loop that prints all the items stored in a list:
QList<QString> list; list.append(“January”); list.append(“February”); ... list.append(“December”);
QList<QString>::iterator i; for (i = list.begin(); i != list.end(); ++i) cout << *i << endl;
Let's see a few examples of things we can do with a QList::iterator that we cannot do with a QList::const_iterator. Here's an example that increments every value stored in a QList<int> by 2:
QList<int>::iterator i; for (i = list.begin(); i != list.end(); ++i) *i += 2;
Most QList functions accept an integer index rather than an iterator. For that reason, iterators are rarely useful in connection with QList. One place where STL-style iterators do make sense is as arguments to generic algorithms.
For example, here's how to delete all the widgets stored in a QList<QWidget *>:
QList<QWidget *> list; ... qDeleteAll(list.begin(), list.end());
Multiple iterators can be used on the same list. However, be aware that any non-const function call performed on the QList will render all existing iterators undefined. If you need to keep iterators over a long period of time, we recommend that you use QLinkedList rather than QList.
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.
Implementations§
source§impl Iterator
impl Iterator
sourcepub unsafe fn add_assign(&self, j: c_longlong) -> Ref<Iterator>
pub unsafe fn add_assign(&self, j: c_longlong) -> Ref<Iterator>
Advances the iterator by j items. (If j is negative, the iterator goes backward.)
Calls C++ function: QList<int>::iterator& QList<int>::iterator::operator+=(long long j)
.
Warning: no exact match found in C++ documentation. Below is the C++ documentation for iterator &iterator::operator+=(int j)
:
Advances the iterator by j items. (If j is negative, the iterator goes backward.)
See also operator-=() and operator+().
sourcepub unsafe fn copy_from(
&self,
other: impl CastInto<Ref<Iterator>>
) -> Ref<Iterator>
pub unsafe fn copy_from( &self, other: impl CastInto<Ref<Iterator>> ) -> Ref<Iterator>
The QList::iterator class provides an STL-style non-const iterator for QList and QQueue.
Calls C++ function: QList<int>::iterator& QList<int>::iterator::operator=(const QList<int>::iterator& other)
.
The QList::iterator class provides an STL-style non-const iterator for QList and QQueue.
QList features both STL-style iterators and Java-style iterators. The STL-style iterators are more low-level and more cumbersome to use; on the other hand, they are slightly faster and, for developers who already know STL, have the advantage of familiarity.
QList<T>::iterator allows you to iterate over a QList<T> (or QQueue<T>) and to modify the list item associated with the iterator. If you want to iterate over a const QList, use QList::const_iterator instead. It is generally good practice to use QList::const_iterator on a non-const QList as well, unless you need to change the QList through the iterator. Const iterators are slightly faster, and can improve code readability.
The default QList::iterator constructor creates an uninitialized iterator. You must initialize it using a QList function like QList::begin(), QList::end(), or QList::insert() before you can start iterating. Here's a typical loop that prints all the items stored in a list:
QList<QString> list; list.append(“January”); list.append(“February”); ... list.append(“December”);
QList<QString>::iterator i; for (i = list.begin(); i != list.end(); ++i) cout << *i << endl;
Let's see a few examples of things we can do with a QList::iterator that we cannot do with a QList::const_iterator. Here's an example that increments every value stored in a QList<int> by 2:
QList<int>::iterator i; for (i = list.begin(); i != list.end(); ++i) *i += 2;
Most QList functions accept an integer index rather than an iterator. For that reason, iterators are rarely useful in connection with QList. One place where STL-style iterators do make sense is as arguments to generic algorithms.
For example, here's how to delete all the widgets stored in a QList<QWidget *>:
QList<QWidget *> list; ... qDeleteAll(list.begin(), list.end());
Multiple iterators can be used on the same list. However, be aware that any non-const function call performed on the QList will render all existing iterators undefined. If you need to keep iterators over a long period of time, we recommend that you use QLinkedList rather than QList.
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.
sourcepub unsafe fn dec(&self) -> Ref<Iterator>
pub unsafe fn dec(&self) -> Ref<Iterator>
The prefix -- operator (--i
) makes the preceding item current and returns an iterator pointing to the new current item.
Calls C++ function: QList<int>::iterator& QList<int>::iterator::operator--()
.
The prefix – operator (–i
) makes the preceding item current and returns an iterator pointing to the new current item.
Calling this function on QHash::begin() leads to undefined results.
See also operator++().
sourcepub unsafe fn dec_postfix(&self, arg1: c_int) -> CppBox<Iterator>
pub unsafe fn dec_postfix(&self, arg1: c_int) -> CppBox<Iterator>
This is an overloaded function.
Calls C++ function: QList<int>::iterator QList<int>::iterator::operator--(int arg1)
.
This is an overloaded function.
The postfix -- operator (i--
) makes the preceding item current and returns an iterator pointing to the previously current item.
sourcepub unsafe fn inc(&self) -> Ref<Iterator>
pub unsafe fn inc(&self) -> Ref<Iterator>
The prefix ++ operator (++i
) advances the iterator to the next item in the hash and returns an iterator to the new current item.
Calls C++ function: QList<int>::iterator& QList<int>::iterator::operator++()
.
The prefix ++ operator (++i
) advances the iterator to the next item in the hash and returns an iterator to the new current item.
Calling this function on QHash::end() leads to undefined results.
See also operator--().
sourcepub unsafe fn inc_postfix(&self, arg1: c_int) -> CppBox<Iterator>
pub unsafe fn inc_postfix(&self, arg1: c_int) -> CppBox<Iterator>
This is an overloaded function.
Calls C++ function: QList<int>::iterator QList<int>::iterator::operator++(int arg1)
.
This is an overloaded function.
The postfix ++ operator (i++
) advances the iterator to the next item in the hash and returns an iterator to the previously current item.
sourcepub unsafe fn index(&self, j: c_longlong) -> *mut c_int
pub unsafe fn index(&self, j: c_longlong) -> *mut c_int
Returns a modifiable reference to the item at offset j from the item pointed to by this iterator (the item at position *this + j
).
Calls C++ function: int& QList<int>::iterator::operator[](long long j) const
.
Warning: no exact match found in C++ documentation. Below is the C++ documentation for QJsonValueRef iterator::operator[](int j) const
:
Returns a modifiable reference to the item at offset j from the item pointed to by this iterator (the item at position *this + j
).
This function is provided to make QJsonArray iterators behave like C++ pointers.
The return value is of type QJsonValueRef, a helper class for QJsonArray and QJsonObject. When you get an object of type QJsonValueRef, you can use it as if it were a reference to a QJsonValue. If you assign to it, the assignment will apply to the character in the QJsonArray of QJsonObject from which you got the reference.
See also operator+().
sourcepub unsafe fn indirection(&self) -> *mut c_int
pub unsafe fn indirection(&self) -> *mut c_int
Returns a modifiable reference to the current item's value.
Calls C++ function: int& QList<int>::iterator::operator*() const
.
sourcepub unsafe fn new() -> CppBox<Iterator>
pub unsafe fn new() -> CppBox<Iterator>
Constructs an uninitialized iterator.
Calls C++ function: [constructor] void QList<int>::iterator::iterator()
.
Constructs an uninitialized iterator.
Functions like operator*() and operator++() should not be called on an uninitialized iterator. Use operator=() to assign a value to it before using it.
See also QList::begin() and QList::end().
sourcepub unsafe fn new_copy(o: impl CastInto<Ref<Iterator>>) -> CppBox<Iterator>
pub unsafe fn new_copy(o: impl CastInto<Ref<Iterator>>) -> CppBox<Iterator>
Calls C++ function: [constructor] void QList<int>::iterator::iterator(const QList<int>::iterator& o)
.
sourcepub unsafe fn struct_deref(&self) -> *mut c_int
pub unsafe fn struct_deref(&self) -> *mut c_int
Returns a pointer to the current item's value.
Calls C++ function: int* QList<int>::iterator::operator->() const
.
Returns a pointer to the current item’s value.
See also value().
sourcepub unsafe fn sub_assign(&self, j: c_longlong) -> Ref<Iterator>
pub unsafe fn sub_assign(&self, j: c_longlong) -> Ref<Iterator>
Makes the iterator go back by j items. (If j is negative, the iterator goes forward.)
Calls C++ function: QList<int>::iterator& QList<int>::iterator::operator-=(long long j)
.
Warning: no exact match found in C++ documentation. Below is the C++ documentation for iterator &iterator::operator-=(int j)
:
Makes the iterator go back by j items. (If j is negative, the iterator goes forward.)
See also operator+=() and operator-().
Trait Implementations§
source§impl CppDeletable for Iterator
impl CppDeletable for Iterator
source§unsafe fn delete(&self)
unsafe fn delete(&self)
The QList::iterator class provides an STL-style non-const iterator for QList and QQueue.
Calls C++ function: [destructor] void QList<int>::iterator::~iterator()
.
The QList::iterator class provides an STL-style non-const iterator for QList and QQueue.
QList features both STL-style iterators and Java-style iterators. The STL-style iterators are more low-level and more cumbersome to use; on the other hand, they are slightly faster and, for developers who already know STL, have the advantage of familiarity.
QList<T>::iterator allows you to iterate over a QList<T> (or QQueue<T>) and to modify the list item associated with the iterator. If you want to iterate over a const QList, use QList::const_iterator instead. It is generally good practice to use QList::const_iterator on a non-const QList as well, unless you need to change the QList through the iterator. Const iterators are slightly faster, and can improve code readability.
The default QList::iterator constructor creates an uninitialized iterator. You must initialize it using a QList function like QList::begin(), QList::end(), or QList::insert() before you can start iterating. Here's a typical loop that prints all the items stored in a list:
QList<QString> list; list.append(“January”); list.append(“February”); ... list.append(“December”);
QList<QString>::iterator i; for (i = list.begin(); i != list.end(); ++i) cout << *i << endl;
Let's see a few examples of things we can do with a QList::iterator that we cannot do with a QList::const_iterator. Here's an example that increments every value stored in a QList<int> by 2:
QList<int>::iterator i; for (i = list.begin(); i != list.end(); ++i) *i += 2;
Most QList functions accept an integer index rather than an iterator. For that reason, iterators are rarely useful in connection with QList. One place where STL-style iterators do make sense is as arguments to generic algorithms.
For example, here's how to delete all the widgets stored in a QList<QWidget *>:
QList<QWidget *> list; ... qDeleteAll(list.begin(), list.end());
Multiple iterators can be used on the same list. However, be aware that any non-const function call performed on the QList will render all existing iterators undefined. If you need to keep iterators over a long period of time, we recommend that you use QLinkedList rather than QList.
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.
source§impl Decrement for Iterator
impl Decrement for Iterator
source§unsafe fn dec(&self) -> Ref<Iterator>
unsafe fn dec(&self) -> Ref<Iterator>
The prefix -- operator (--i
) makes the preceding item current and returns an iterator pointing to the new current item.
Calls C++ function: QList<int>::iterator& QList<int>::iterator::operator--()
.
The prefix – operator (–i
) makes the preceding item current and returns an iterator pointing to the new current item.
Calling this function on QHash::begin() leads to undefined results.
See also operator++().
source§impl Ge<Ref<ConstIterator>> for Iterator
impl Ge<Ref<ConstIterator>> for Iterator
source§unsafe fn ge(&self, other: &Ref<ConstIterator>) -> bool
unsafe fn ge(&self, other: &Ref<ConstIterator>) -> bool
Returns true
if the item pointed to by this iterator is greater than or equal to the item pointed to by the other iterator.
Calls C++ function: bool QList<int>::iterator::operator>=(const QList<int>::const_iterator& other) const
.
Returns true
if the item pointed to by this iterator is greater than or equal to the item pointed to by the other iterator.
source§impl Ge<Ref<Iterator>> for Iterator
impl Ge<Ref<Iterator>> for Iterator
source§unsafe fn ge(&self, other: &Ref<Iterator>) -> bool
unsafe fn ge(&self, other: &Ref<Iterator>) -> bool
Returns true
if the item pointed to by this iterator is greater than or equal to the item pointed to by the other iterator.
Calls C++ function: bool QList<int>::iterator::operator>=(const QList<int>::iterator& other) const
.
Returns true
if the item pointed to by this iterator is greater than or equal to the item pointed to by the other iterator.
source§impl Gt<Ref<ConstIterator>> for Iterator
impl Gt<Ref<ConstIterator>> for Iterator
source§unsafe fn gt(&self, other: &Ref<ConstIterator>) -> bool
unsafe fn gt(&self, other: &Ref<ConstIterator>) -> bool
Returns true
if the item pointed to by this iterator is greater than the item pointed to by the other iterator.
Calls C++ function: bool QList<int>::iterator::operator>(const QList<int>::const_iterator& other) const
.
Returns true
if the item pointed to by this iterator is greater than the item pointed to by the other iterator.
source§impl Gt<Ref<Iterator>> for Iterator
impl Gt<Ref<Iterator>> for Iterator
source§unsafe fn gt(&self, other: &Ref<Iterator>) -> bool
unsafe fn gt(&self, other: &Ref<Iterator>) -> bool
Returns true
if the item pointed to by this iterator is greater than the item pointed to by the other iterator.
Calls C++ function: bool QList<int>::iterator::operator>(const QList<int>::iterator& other) const
.
Returns true
if the item pointed to by this iterator is greater than the item pointed to by the other iterator.
source§impl Increment for Iterator
impl Increment for Iterator
source§unsafe fn inc(&self) -> Ref<Iterator>
unsafe fn inc(&self) -> Ref<Iterator>
The prefix ++ operator (++i
) advances the iterator to the next item in the hash and returns an iterator to the new current item.
Calls C++ function: QList<int>::iterator& QList<int>::iterator::operator++()
.
The prefix ++ operator (++i
) advances the iterator to the next item in the hash and returns an iterator to the new current item.
Calling this function on QHash::end() leads to undefined results.
See also operator--().
source§impl Indirection for Iterator
impl Indirection for Iterator
source§unsafe fn indirection(&self) -> *mut c_int
unsafe fn indirection(&self) -> *mut c_int
Returns a modifiable reference to the current item's value.
Calls C++ function: int& QList<int>::iterator::operator*() const
.
source§impl Le<Ref<ConstIterator>> for Iterator
impl Le<Ref<ConstIterator>> for Iterator
source§unsafe fn le(&self, other: &Ref<ConstIterator>) -> bool
unsafe fn le(&self, other: &Ref<ConstIterator>) -> bool
Returns true
if the item pointed to by this iterator is less than or equal to the item pointed to by the other iterator.
Calls C++ function: bool QList<int>::iterator::operator<=(const QList<int>::const_iterator& other) const
.
Returns true
if the item pointed to by this iterator is less than or equal to the item pointed to by the other iterator.
source§impl Le<Ref<Iterator>> for Iterator
impl Le<Ref<Iterator>> for Iterator
source§unsafe fn le(&self, other: &Ref<Iterator>) -> bool
unsafe fn le(&self, other: &Ref<Iterator>) -> bool
Returns true
if the item pointed to by this iterator is less than or equal to the item pointed to by the other iterator.
Calls C++ function: bool QList<int>::iterator::operator<=(const QList<int>::iterator& other) const
.
Returns true
if the item pointed to by this iterator is less than or equal to the item pointed to by the other iterator.
source§impl Lt<Ref<ConstIterator>> for Iterator
impl Lt<Ref<ConstIterator>> for Iterator
source§unsafe fn lt(&self, other: &Ref<ConstIterator>) -> bool
unsafe fn lt(&self, other: &Ref<ConstIterator>) -> bool
Returns true
if the item pointed to by this iterator is less than the item pointed to by the other iterator.
Calls C++ function: bool QList<int>::iterator::operator<(const QList<int>::const_iterator& other) const
.
Returns true
if the item pointed to by this iterator is less than the item pointed to by the other iterator.
source§impl Lt<Ref<Iterator>> for Iterator
impl Lt<Ref<Iterator>> for Iterator
source§unsafe fn lt(&self, other: &Ref<Iterator>) -> bool
unsafe fn lt(&self, other: &Ref<Iterator>) -> bool
Returns true
if the item pointed to by this iterator is less than the item pointed to by the other iterator.
Calls C++ function: bool QList<int>::iterator::operator<(const QList<int>::iterator& other) const
.
Returns true
if the item pointed to by this iterator is less than the item pointed to by the other iterator.
source§impl PartialEq<Ref<ConstIterator>> for Iterator
impl PartialEq<Ref<ConstIterator>> for Iterator
source§fn eq(&self, o: &Ref<ConstIterator>) -> bool
fn eq(&self, o: &Ref<ConstIterator>) -> bool
Returns true
if other points to the same item as this iterator; otherwise returns false
.
Calls C++ function: bool QList<int>::iterator::operator==(const QList<int>::const_iterator& o) const
.
Returns true
if other points to the same item as this iterator; otherwise returns false
.
See also operator!=().
source§impl PartialEq<Ref<Iterator>> for Iterator
impl PartialEq<Ref<Iterator>> for Iterator
source§fn eq(&self, o: &Ref<Iterator>) -> bool
fn eq(&self, o: &Ref<Iterator>) -> bool
Returns true
if other points to the same item as this iterator; otherwise returns false
.
Calls C++ function: bool QList<int>::iterator::operator==(const QList<int>::iterator& o) const
.
Returns true
if other points to the same item as this iterator; otherwise returns false
.
See also operator!=().