QtPromise::all

Since: 0.5.0

QtPromise::all(Sequence<QPromise<T>> promises) -> QPromise<QVector<T>>
QtPromise::all(Sequence<QPromise<void>> promises) -> QPromise<void>

Returns a QPromise<QVector<T>> (or QPromise<void>) that fulfills when all promises of (the same) type T have been fulfilled. The output value is a vector containing all the values of promises, in the same order, i.e., at the respective positions to the original sequence, regardless of completion order.

If any of the given promises fail, output immediately rejects with the error of the promise that rejected, whether or not the other promises are resolved.

Sequence is any STL compatible container (eg. QVector, QList, std::vector, etc.)

QVector<QPromise<QByteArray> > promises{
    download(QUrl("http://a...")),
    download(QUrl("http://b...")),
    download(QUrl("http://c..."))
};

auto output = QtPromise::all(promises);

// output type: QPromise<QVector<QByteArray>>
output.then([](const QVector<QByteArray>& res) {
    // {...}
});