Question

I have this code:

#ifndef FUNCSTARTER_H
#define FUNCSTARTER_H

#endif // FUNCSTARTER_H

#include <QObject>

class FunctionStarter : public QObject
{
    Q_OBJECT
public:
    FunctionStarter() {}
    virtual ~FunctionStarter() {}

public slots:
    void FuncStart(start) {
        Start the function
    }
};

In the FuncStart function, you would put your function in as a parameter and then it would execute the parameter (aka the function). How would I do this?

Answer 1

You’d pass the function pointer as parameter. This is called a callback.

typedef void(*FunPtr)();  //provide a friendly name for the type

class FunctionStarter : public QObject
{
public:
    void FuncStart(FunPtr) { //takes a function pointer as parameter
        FunPtr();  //invoke the function
    }
};

void foo();

int main()
{
    FunctionStarter fs;
    fs.FuncStart(&foo); //pass the pointer to the function as parameter
                        //in C++, the & is optional, put here for clarity
}