Use callback function in my class

cocos2d-x C++
1

Hello, I want to use callback function in my class, but I don’t know how.
Example:

Class myClass
{ 
    myClass( /*here I want to pass callback func arg */)
    { _callBackFunc = /* arg */ }
   /* type */ _callBackFunc;
    void func() { /* here I want to call _callBackFunc */ }
}

What type is callback func?
How to call it?
Ps: sorry for my English. Thank you.

2

You can use std::function:

class myClass{
   std::function<void()> callback;
   void func(){  
        callback();  
   };
}

to set callback use std::bind

callback = std::bind(&SomeClass::someFunction, someClassInstance);
3

When calling an std::function it is recommended to test it is valid:

if(callback) { callback(); }

(std::function implements operator bool so we don’t need an explicit comparison)

You can also use lambda’s inline to implement functions:

auto function = [=]()
{
   printf("I'm a function!");
};

Further reading:
http://en.cppreference.com/w/cpp/utility/functional/function
http://en.cppreference.com/w/cpp/language/lambda

4

Thank you!