I'm trying to make a simple callback in C++ but I'm having issues doing it as I want to.
Essentially I want something like this:
class A{
void A::AddCallback(void (*callBackFunction)(string)){
/*Code goes here*/
}
}
And class B
#include "A.h"
class B{
B::B(){
A childObject;
childObject(MyCallBackFunction);
}
B::MyCallBackFunction(string arg){
/*Code goes here*/
}
}
I know that usually you would want to define the header of AddCallback with something like B::callBackFunction but I do need to import A in B so I it would be awkward to have both classes import each other. I know I've seen this before but I cant get the syntax right
Here is one option using a static member function:
#include <string>
struct A
{
void AddCallback(void (*cb)(std::string));
};
struct B
{
A a;
B() { a.AddCallback(&B::MyFun); }
static void MyFun(std::string);
};
If you want a non-static member function, then you first need to decide on which instance of B you want the member function to be invoked. For example, to invoke it on the object whose constructor registers the callback:
#include <functional>
#include <string>
struct A
{
void AddCallback(std::function<void(std::string)>);
};
struct B
{
A a;
B() { a.AddCallback(std::bind(&B::MyFun, this, std::placeholders::_1)); }
void MyFun(std::string);
};
Collected from the Internet
Please contact [email protected] to delete if infringement.
Comments