QT - Execute a function from a task thread in the main thread context. This is useful to update UI, without cross thread errors.

ThreadUISwitch.cpp

void ThreadToolUI::PostToMainThread(const std::function<void()> & fun)
{
    QObject signalSource;
    QObject::connect(&signalSource, &QObject::destroyed, qApp, [=](QObject*){
        fun();
    });
}

Task::run<void>([=]() {
  qDebug() << "Current therad is task thread";
  ThreadToolUI::PostToMainThread([=]() {
      qDebug() << "Current therad is main thread";
  });
}).start();