- Qt 5.15
- Qt Core
- C++ Classes
- QSequentialIterable
- Qt 5.15.18 Reference Documentation

# QSequentialIterable Class

The QSequentialIterable class is an iterable interface for a container in a QVariant. More...

Header: | #include <QSequentialIterable>
qmake: | QT += core
Since: | Qt 5.2

This class was introduced in Qt 5.2.

- List of all members, including inherited members

## Public Types

struct | const_iterator

## Public Functions

QVariant | at(int idx) const
const_iterator | begin() const
bool | canReverseIterate() const
const_iterator | end() const
int | size() const

## Detailed Description

This class allows several methods of accessing the elements of a container held within a QVariant. An instance of QSequentialIterable can be extracted from a QVariant if it can be converted to a QVariantList.

     QList<int> intList = {7, 11, 42};

     QVariant variant = QVariant::fromValue(intList);
     if (variant.canConvert<QVariantList>()) {
         QSequentialIterable iterable = variant.value<QSequentialIterable>();
         // Can use foreach:
         foreach (const QVariant &v, iterable) {
             qDebug() << v;
         }
         // Can use C++11 range-for:
         for (const QVariant &v : iterable) {
             qDebug() << v;
         }
         // Can use iterators:
         QSequentialIterable::const_iterator it = iterable.begin();
         const QSequentialIterable::const_iterator end = iterable.end();
         for ( ; it != end; ++it) {
             qDebug() << *it;
         }
     }

The container itself is not copied before iterating over it.

See also QVariant.

## Member Function Documentation

### QVariant QSequentialIterable::at(int idx) const

Returns the element at position idx in the container.

### const_iterator QSequentialIterable::begin() const

Returns a QSequentialIterable::const_iterator for the beginning of the container. This can be used in stl-style iteration.

See also end().

### bool QSequentialIterable::canReverseIterate() const

Returns whether it is possible to iterate over the container in reverse. This corresponds to the std::bidirectional_iterator_tag iterator trait of the const_iterator of the container.

### const_iterator QSequentialIterable::end() const

Returns a QSequentialIterable::const_iterator for the end of the container. This can be used in stl-style iteration.

See also begin().

### int QSequentialIterable::size() const

Returns the number of elements in the container.