AfterRequest Example

 // Copyright (C) 2020 Mikhail Svetkin <mikhail.svetkin@gmail.com>
 // Copyright (C) 2018 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause

 #include <QtCore>
 #include <QtHttpServer>

 int main(int argc, char *argv[])
 {
     QCoreApplication app(argc, argv);

     QHttpServer httpServer;
     httpServer.route("/", []() {
         return "Hello world";
     });

     httpServer.afterRequest([](QHttpServerResponse &&resp) {
         resp.setHeader("Server", "Super server!");
         return std::move(resp);
     });

     const auto port = httpServer.listen(QHostAddress::Any);
     if (!port) {
         qDebug() << QCoreApplication::translate(
                 "QHttpServerExample", "Server failed to listen on a port.");
         return 0;
     }

     qDebug() << QCoreApplication::translate(
             "QHttpServerExample", "Running on http://127.0.0.1:%1/ (Press CTRL+C to quit)").arg(port);

     return app.exec();
 }