How to include a feature in a slot?

Question

Qt

How to fix the error?

Answer 1

It is necessary to make the class declaration in the *.h file, and the implementation in *.cpp.

Answer 2

#include <QCoreApplication>
#include <QDebug>
#include <QTimer>

void foo()
{
  qDebug() << "Bingo";
}

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

  QTimer timer;
  QObject::connect(&timer, &QTimer::timeout, std::bind(foo));
  timer.start(1000);

  return a.exec();
}