QAssociativeIterable Class

Detailed Description

The QAssociativeIterable class is an iterable interface for an associative container in a QVariant.

This class allows several methods of accessing the elements of an associative container held within a QVariant. An instance of QAssociativeIterable can be extracted from a QVariant if it can be converted to a QVariantHash or QVariantMap.

QHash<int, QString> mapping;
mapping.insert(7, "Seven");
mapping.insert(11, "Eleven");
mapping.insert(42, "Forty-two");

QVariant variant = QVariant::fromValue(mapping);
if (variant.canConvert<QVariantHash>()) {
    QAssociativeIterable iterable = variant.value<QAssociativeIterable>();
    // Can use foreach over the values:
    foreach (const QVariant &v, iterable) {
        qDebug() << v;
    }
    // Can use C++11 range-for over the values:
    for (const QVariant &v : iterable) {
        qDebug() << v;
    }
    // Can use iterators:
    QAssociativeIterable::const_iterator it = iterable.begin();
    const QAssociativeIterable::const_iterator end = iterable.end();
    for ( ; it != end; ++it) {
        qDebug() << *it; // The current value
        qDebug() << it.key();
        qDebug() << it.value();
    }
}

The container itself is not copied before iterating over it.