How to create a thread of a pointer to a function C++

Question

I know that in order to create a thread of a method on an Object I can do it in this way:

#include <thread> 
using namespace std;

class Character
{
public:
    void myFunction(int a){ /* */ }

    void startThreadMyFunction(int a){
      thread Mf1(&Character::myFunction, this, a);
    }
};

Also I know that in order to have a pointer to a function in my class I can do it in this way:

#include <thread>  
using namespace std;

class Character
{
private:
    void (*FMoveForward)(int);// Pointer to a function.
public:
    void setCommands(void(mf)(int delay)){//This function sets the pointer.
      FMoveForward = mf;
    }
    void MoveForward(int delay){
      FMoveForward(delay);// Here a call my function with my pointer to function.
    }
};

My problem is that all the time when I try to use both of these things together the Visual Studio 13 compiler always complain about the sintaxe.

#include <iostream>
using namespace std;

class Character
{
private:
    void (*FMoveForward)(int);
public:
    void setCommands(void(mf)(int delay)){
      FMoveForward = mf;
    }
    void MoveForward(int delay){
      thread Mf1(&Character::FMoveForward , this, delay);// The VS 13 Complain because the sintaxe os this line.
    }

};

Does anyone knows how to solve it? TY in advanced...

Answer 1

This

thread Mf1(&Character::FMoveForward ,0 this, delay);// The VS 13 Complain because the sintaxe os this line.

happens to have a syntax error: 0 this

Answer 2

The problem is that pointers to member functions are not pointers to free functions. std::thread can use both, but you need to be consistent.

In your first example, you have a pointer to a member function. OK.

In your second example, you have a pointer to a free function. Also OK.

In your third example, FMoveForward is a pointer to a free function. &Character::FMoveForward is a pointer to a pointer. That's not going to work.

If you want to store &Character::myFunction , you would need a void (Character::*FMoveForward)(int); member. That's a pointer to a member function