QCoro 0.1.0 Release Announcement

I'm happy to announce first release of QCoro, a library that provides C++ coroutine support for Qt.

You can download QCoro 0.1.0 here or check the latest sources on QCoro GitHub.

I have talked about QCoro (and C++ coroutines in general) recently at KDE Akademy, you can view the recording of my talk on YouTube.

In general, QCoro provides coroutine support for various asynchronous operations provided by Qt. Since Qt doesn't support coroutines by default, QCoro provides the necessary "glue" between native Qt types and the C++ coroutine machinery, making it possible to use Qt types with coroutines easily.

QCoro provides coroutine support for asynchronous operations of QIODevice, QNetworkReply, QProcess, QDBusPendingReply, QTimer and more. Take a look at the documentation for detailed description and list of all currently supported Qt types.

A brief example from our documentation that demonstrates how using coroutines makes handling asynchronous operations in Qt simpler:

This is a (simplified) example of how we do network requests with Qt normally, using signals and slots:

QNetworkAccessManager *manager = new QNetworkAccessManager(this);
QNetworkReply *reply = manager->get(url);
connect(reply, &QNetworkReply::finished, this,
        [this, reply]() {
            const auto data = reply->readAll();
            doSomethingWithData(data);
            reply->deleteLater();
        });

And this is the same code, written using C++ coroutines:

QNetworkAccessManager networkAccessManager;
QNetworkReply *reply = co_await networkAccessManager.get(url);
const auto data = reply->readAll();
doSomethingWithData(data);
reply->deleteLater();

The co_await keyword here is the key here: it asynchronously waits for the reply to finish. During the wait, the execution returns to the caller, which could be the Qt event loop, which means that even if this code looks synchronous, in fact it won't block the event loop while keeping the code simple to read and understand.