Event is a header only library that makes it easy to create event driven programs in C++11.

Simply include event.hpp, there are no dependencies (other than a compiler that supports the memory and functional C++11 standard library components).

Create an event by using the Event template class:

Event<> my_event;

Events can have none or many arguments of any type you would pass in to a function:

Event<int, int&, const int&, int*, CustomClass> my_event;

Firing an Event will synchronously execute all bound functions. Firing an Event requires supplying the arguments specified in the template. These values will be passed in to the bound functions.

Event<int> my_event;
my_event.fire(0);
my_event.fire(1);

Functions that take the same arguments and return void may be bound to the Event. A bound function will automatically be unbound when the bind ( std::shared_ptr<Event<Args...>::Bind>) falls out of scope. Binds can safely outlive the respective Event. Alternatively a function can be permanently bound using the Event::permanent_bind method.

Event<int> my_event;
{
	// bind for the duration of the bind object
	auto bind = my_event.bind([](int input){
		std::cout << "temporary:" << input << std::endl;
	});
	// permanently bind
	my_event.permanent_bind([](int input){
		std::cout << "permanent: " << input << std::endl;
	});
	// fire, both binds will execute
	my_event.fire(0);
}
// fire, only the permanent bind will execute as the temporary bind has fallen
// out of scope
my_event.fire(1);

The above code will output:

temporary: 0
permanent: 0
permanent: 1

It is also safe to bind and unbind in a function that is bound to an Event, even while that Event is firing:

std::shared_ptr<Event<>::Bind> bind = 0;
Event<> my_event;
// bind a function that automatically unbinds itself after executing once
bind = my_event.bind([&bind](){
	std::cout << "hello world" << std::endl;
	bind = 0;
});
my_event.fire();
my_event.fire();

The above code will output:

hello world

Tests are successful if there is no output. Example build command with gcc on windows:

g++ -ggdb -Wall --std=c++11 test.cpp -o test.exe