Struct qt_widgets::q_list_of_q_abstract_button::ConstIterator

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

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

C++ class: QList<QAbstractButton*>::const_iterator.

C++ documentation:

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

QList provides 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>::const_iterator allows you to iterate over a QList<T> (or a QQueue<T>). If you want to modify the QList as you iterate over it, use QList::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::const_iterator constructor creates an uninitialized iterator. You must initialize it using a QList function like QList::constBegin(), QList::constEnd(), 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>::const_iterator i;
for (i = list.constBegin(); i != list.constEnd(); ++i)
      cout << *i << endl;

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.constBegin(), list.constEnd());

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 ConstIterator

pub unsafe fn add_assign(&self, j: c_longlong) -> Ref<ConstIterator>

Advances the iterator by j items.

Calls C++ function: QList<QAbstractButton*>::const_iterator& QList<QAbstractButton*>::const_iterator::operator+=(long long j).

Warning: no exact match found in C++ documentation. Below is the C++ documentation for const_iterator &const_iterator::operator+=(int j):

Advances the iterator by j items.

See also operator-=() and operator+().

pub unsafe fn copy_from(
    &self,
    other: impl CastInto<Ref<ConstIterator>>
) -> Ref<ConstIterator>

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

Calls C++ function: QList<QAbstractButton*>::const_iterator& QList<QAbstractButton*>::const_iterator::operator=(const QList<QAbstractButton*>::const_iterator& other).

C++ documentation:

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

QList provides 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>::const_iterator allows you to iterate over a QList<T> (or a QQueue<T>). If you want to modify the QList as you iterate over it, use QList::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::const_iterator constructor creates an uninitialized iterator. You must initialize it using a QList function like QList::constBegin(), QList::constEnd(), 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>::const_iterator i;
for (i = list.constBegin(); i != list.constEnd(); ++i)
      cout << *i << endl;

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.constBegin(), list.constEnd());

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<ConstIterator>

The prefix -- operator (--it) makes the preceding item current and returns an iterator to the new current item.

Calls C++ function: QList<QAbstractButton*>::const_iterator& QList<QAbstractButton*>::const_iterator::operator--().

C++ documentation:

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++().

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

This is an overloaded function.

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

C++ documentation:

This is an overloaded function.

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

pub unsafe fn inc(&self) -> Ref<ConstIterator>

The prefix ++ operator (++it) advances the iterator to the next item in the container and returns an iterator to the new current item.

Calls C++ function: QList<QAbstractButton*>::const_iterator& QList<QAbstractButton*>::const_iterator::operator++().

C++ documentation:

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--().

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

This is an overloaded function.

Calls C++ function: QList<QAbstractButton*>::const_iterator QList<QAbstractButton*>::const_iterator::operator++(int arg1).

C++ documentation:

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.

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

Returns the item at offset j from the item pointed to by this iterator (the item at position *this + j).

Calls C++ function: const QAbstractButton*& QList<QAbstractButton*>::const_iterator::operator[](long long j) const.

Warning: no exact match found in C++ documentation. Below is the C++ documentation for QJsonValue const_iterator::operator[](int j) const:

Returns 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.

See also operator+().

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

Returns the current value, converted to a QVariant.

Calls C++ function: const QAbstractButton*& QList<QAbstractButton*>::const_iterator::operator*() const.

C++ documentation:

Returns the current value, converted to a QVariant.

pub unsafe fn new_0a() -> CppBox<ConstIterator>

Constructs an uninitialized iterator.

Calls C++ function: [constructor] void QList<QAbstractButton*>::const_iterator::const_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::constBegin() and QList::constEnd().

pub unsafe fn new_1a(o: impl CastInto<Ref<Iterator>>) -> CppBox<ConstIterator>

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

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

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

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

Returns a pointer to the current result.

Calls C++ function: const QAbstractButton** QList<QAbstractButton*>::const_iterator::operator->() const.

C++ documentation:

Returns a pointer to the current result.

pub unsafe fn sub_assign(&self, j: c_longlong) -> Ref<ConstIterator>

Makes the iterator go back by j items.

Calls C++ function: QList<QAbstractButton*>::const_iterator& QList<QAbstractButton*>::const_iterator::operator-=(long long j).

Warning: no exact match found in C++ documentation. Below is the C++ documentation for const_iterator &const_iterator::operator-=(int j):

Makes the iterator go back by j items.

See also operator+=() and operator-().

Trait Implementations

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

type Output = CppBox<ConstIterator>

The resulting type after applying the + operator.

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

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

impl CppDeletable for ConstIterator

unsafe fn delete(&self)

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

Calls C++ function: [destructor] void QList<QAbstractButton*>::const_iterator::~const_iterator().

C++ documentation:

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

QList provides 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>::const_iterator allows you to iterate over a QList<T> (or a QQueue<T>). If you want to modify the QList as you iterate over it, use QList::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::const_iterator constructor creates an uninitialized iterator. You must initialize it using a QList function like QList::constBegin(), QList::constEnd(), 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>::const_iterator i;
for (i = list.constBegin(); i != list.constEnd(); ++i)
      cout << *i << endl;

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.constBegin(), list.constEnd());

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 ConstIterator

type Output = Ref<ConstIterator>

Output type.

unsafe fn dec(&self) -> Ref<ConstIterator>

The prefix -- operator (--it) makes the preceding item current and returns an iterator to the new current item.

Calls C++ function: QList<QAbstractButton*>::const_iterator& QList<QAbstractButton*>::const_iterator::operator--().

C++ documentation:

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++().

impl Ge<Ref<ConstIterator>> for ConstIterator

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<QAbstractButton*>::const_iterator::operator>=(const QList<QAbstractButton*>::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 Gt<Ref<ConstIterator>> for ConstIterator

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<QAbstractButton*>::const_iterator::operator>(const QList<QAbstractButton*>::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 Increment for ConstIterator

type Output = Ref<ConstIterator>

Output type.

unsafe fn inc(&self) -> Ref<ConstIterator>

The prefix ++ operator (++it) advances the iterator to the next item in the container and returns an iterator to the new current item.

Calls C++ function: QList<QAbstractButton*>::const_iterator& QList<QAbstractButton*>::const_iterator::operator++().

C++ documentation:

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--().

impl Indirection for ConstIterator

type Output = *const *mut QAbstractButton

Output type.

unsafe fn indirection(&self) -> *const *mut QAbstractButton

Returns the current value, converted to a QVariant.

Calls C++ function: const QAbstractButton*& QList<QAbstractButton*>::const_iterator::operator*() const.

C++ documentation:

Returns the current value, converted to a QVariant.

impl Le<Ref<ConstIterator>> for ConstIterator

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<QAbstractButton*>::const_iterator::operator<=(const QList<QAbstractButton*>::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 Lt<Ref<ConstIterator>> for ConstIterator

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<QAbstractButton*>::const_iterator::operator<(const QList<QAbstractButton*>::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 PartialEq<Ref<ConstIterator>> for ConstIterator

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<QAbstractButton*>::const_iterator::operator==(const QList<QAbstractButton*>::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<'_> Sub<Ref<ConstIterator>> for &'_ ConstIterator

type Output = c_int

The resulting type after applying the - operator.

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

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

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

type Output = CppBox<ConstIterator>

The resulting type after applying the - operator.

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

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