This is a single header library for an event system or delegates taking inspiration in Epic's Unreal Engine 4 delegate system.

You can just import it to your project and use with without dependencies, defines or anything.

The file is in jsolibrary/src/Events.h

#include "Events.h"

DECLARE_DELEGATE_NO_PARAM(FNoParamDelegate);
DECLARE_DELEGATE_ONE_PARAM(FOneParamDelegate, TYPE);
DECLARE_DELEGATE_TWO_PARAM(FTwoParamDelegate, TYPE1, TYPE2);
DECLARE_DELEGATE_THREE_PARAM(FThreeParamDelegate, TYPE1, TYPE2, TYPE3);

Right now events up to 3 parameters are supported, the number will be increasing over time, so stay tuned!

FOneParamDelegate delegate;

void Callback(int value)
{
  cout << "Callback: " << value << endl;
}

class Foo
{
public:
  void callback(int value)
  {
    cout << value << endl;
  }
};

int main() {
  FOneParam delegate;
  Foo foo;
  delegate.addListener<Foo, &Foo::callback>(&foo);
  delegate.addListener<&Callback>();
 }

delegate.broadcast(0);

0
Callback: 0

1. Remove all bindings of the event

delegate.removeAll();

2. Remove a specific listener binding from delegate

delegate.removeListener<&Callback>();
delegate.removeListener<Foo, &Foo::callback>(&foo);

• Add events with more parameters
• Add remove binding option for an specific listener instead of having to delete them all
• Add remove binding of all listeners of a given instance
• Improve the performance of the events by getting rid of the vector holding all the listeners

• GameProgrammingPatterns
• Giang Tong - CPP event delegate
• Molecular Musings - Generic, type-safe delegates and events in C++