Struct qt_widgets::q_list_of_q_graphics_widget::Iterator

#[repr(C)]pub struct Iterator { /* fields omitted */ }

The QList::iterator class provides an STL-style non-const iterator for QList and QQueue.

C++ class: QList<QGraphicsWidget*>::iterator.

C++ documentation:

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.

Methods

impl 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<QGraphicsWidget*>::iterator& QList<QGraphicsWidget*>::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+().

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<QGraphicsWidget*>::iterator& QList<QGraphicsWidget*>::iterator::operator=(const QList<QGraphicsWidget*>::iterator& other).

C++ documentation:

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.

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<QGraphicsWidget*>::iterator& QList<QGraphicsWidget*>::iterator::operator--().

C++ documentation:

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++().

pub unsafe fn dec_postfix(&self, arg1: c_int) -> CppBox<Iterator>

This is an overloaded function.

Calls C++ function: QList<QGraphicsWidget*>::iterator QList<QGraphicsWidget*>::iterator::operator--(int arg1).

C++ documentation:

This is an overloaded function.

The postfix -- operator (i--) makes the preceding item current and returns an iterator pointing to the previously current item.

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<QGraphicsWidget*>::iterator& QList<QGraphicsWidget*>::iterator::operator++().

C++ documentation:

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--().

pub unsafe fn inc_postfix(&self, arg1: c_int) -> CppBox<Iterator>

This is an overloaded function.

Calls C++ function: QList<QGraphicsWidget*>::iterator QList<QGraphicsWidget*>::iterator::operator++(int arg1).

C++ documentation:

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.

pub unsafe fn index(&self, j: c_longlong) -> *mut *mut QGraphicsWidget

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: QGraphicsWidget*& QList<QGraphicsWidget*>::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+().

pub unsafe fn indirection(&self) -> *mut *mut QGraphicsWidget

Returns a modifiable reference to the current item's value.

Calls C++ function: QGraphicsWidget*& QList<QGraphicsWidget*>::iterator::operator*() const.

C++ documentation:

Returns a modifiable reference to the current item's value.

Same as value().

See also key().

pub unsafe fn new() -> CppBox<Iterator>

Constructs an uninitialized iterator.

Calls C++ function: [constructor] void QList<QGraphicsWidget*>::iterator::iterator().

C++ documentation:

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().

pub unsafe fn new_copy(o: impl CastInto<Ref<Iterator>>) -> CppBox<Iterator>

Calls C++ function: [constructor] void QList<QGraphicsWidget*>::iterator::iterator(const QList<QGraphicsWidget*>::iterator& o).

pub unsafe fn struct_deref(&self) -> *mut *mut QGraphicsWidget

Returns a pointer to the current item's value.

Calls C++ function: QGraphicsWidget** QList<QGraphicsWidget*>::iterator::operator->() const.

C++ documentation:

Returns a pointer to the current item's value.

See also value().

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<QGraphicsWidget*>::iterator& QList<QGraphicsWidget*>::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

impl<'_> Add<i64> for &'_ Iterator

type Output = CppBox<Iterator>

The resulting type after applying the + operator.

fn add(self, j: c_longlong) -> CppBox<Iterator>

Calls C++ function: QList<QGraphicsWidget*>::iterator QList<QGraphicsWidget*>::iterator::operator+(long long j) const.

impl CppDeletable for Iterator

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<QGraphicsWidget*>::iterator::~iterator().

C++ documentation:

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.

impl Decrement for Iterator

type Output = Ref<Iterator>

Output type.

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<QGraphicsWidget*>::iterator& QList<QGraphicsWidget*>::iterator::operator--().

C++ documentation:

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++().

impl Ge<Ref<ConstIterator>> for Iterator

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<QGraphicsWidget*>::iterator::operator>=(const QList<QGraphicsWidget*>::const_iterator& other) const.

C++ documentation:

Returns true if the item pointed to by this iterator is greater than or equal to the item pointed to by the other iterator.

impl Ge<Ref<Iterator>> for Iterator

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<QGraphicsWidget*>::iterator::operator>=(const QList<QGraphicsWidget*>::iterator& other) const.

C++ documentation:

Returns true if the item pointed to by this iterator is greater than or equal to the item pointed to by the other iterator.

impl Gt<Ref<ConstIterator>> for Iterator

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<QGraphicsWidget*>::iterator::operator>(const QList<QGraphicsWidget*>::const_iterator& other) const.

C++ documentation:

Returns true if the item pointed to by this iterator is greater than the item pointed to by the other iterator.

impl Gt<Ref<Iterator>> for Iterator

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<QGraphicsWidget*>::iterator::operator>(const QList<QGraphicsWidget*>::iterator& other) const.

C++ documentation:

Returns true if the item pointed to by this iterator is greater than the item pointed to by the other iterator.

impl Increment for Iterator

type Output = Ref<Iterator>

Output type.

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<QGraphicsWidget*>::iterator& QList<QGraphicsWidget*>::iterator::operator++().

C++ documentation:

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--().

impl Indirection for Iterator

type Output = *mut *mut QGraphicsWidget

Output type.

unsafe fn indirection(&self) -> *mut *mut QGraphicsWidget

Returns a modifiable reference to the current item's value.

Calls C++ function: QGraphicsWidget*& QList<QGraphicsWidget*>::iterator::operator*() const.

C++ documentation:

Returns a modifiable reference to the current item's value.

Same as value().

See also key().

impl Le<Ref<ConstIterator>> for Iterator

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<QGraphicsWidget*>::iterator::operator<=(const QList<QGraphicsWidget*>::const_iterator& other) const.

C++ documentation:

Returns true if the item pointed to by this iterator is less than or equal to the item pointed to by the other iterator.

impl Le<Ref<Iterator>> for Iterator

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<QGraphicsWidget*>::iterator::operator<=(const QList<QGraphicsWidget*>::iterator& other) const.

C++ documentation:

Returns true if the item pointed to by this iterator is less than or equal to the item pointed to by the other iterator.

impl Lt<Ref<ConstIterator>> for Iterator

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<QGraphicsWidget*>::iterator::operator<(const QList<QGraphicsWidget*>::const_iterator& other) const.

C++ documentation:

Returns true if the item pointed to by this iterator is less than the item pointed to by the other iterator.

impl Lt<Ref<Iterator>> for Iterator

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<QGraphicsWidget*>::iterator::operator<(const QList<QGraphicsWidget*>::iterator& other) const.

C++ documentation:

Returns true if the item pointed to by this iterator is less than the item pointed to by the other iterator.

impl PartialEq<Ref<ConstIterator>> for Iterator

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<QGraphicsWidget*>::iterator::operator==(const QList<QGraphicsWidget*>::const_iterator& o) const.

C++ documentation:

Returns true if other points to the same item as this iterator; otherwise returns false.

See also operator!=().

#[must_use]fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<Ref<Iterator>> for Iterator

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<QGraphicsWidget*>::iterator::operator==(const QList<QGraphicsWidget*>::iterator& o) const.

C++ documentation:

Returns true if other points to the same item as this iterator; otherwise returns false.

See also operator!=().

#[must_use]fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<'_> Sub<Ref<Iterator>> for &'_ Iterator

type Output = c_int

The resulting type after applying the - operator.

fn sub(self, j: Ref<Iterator>) -> c_int

Calls C++ function: int QList<QGraphicsWidget*>::iterator::operator-(QList<QGraphicsWidget*>::iterator j) const.

impl<'_> Sub<i64> for &'_ Iterator

type Output = CppBox<Iterator>

The resulting type after applying the - operator.

fn sub(self, j: c_longlong) -> CppBox<Iterator>

Calls C++ function: QList<QGraphicsWidget*>::iterator QList<QGraphicsWidget*>::iterator::operator-(long long j) const.