gistfile1.txt

class SteeringWheel {
public:
	boolean fuzzy;
	SomeExternalResource * resource;

  // copy constructor
	SteeringWheel(const SteeringWheel & other) {
		fuzzy = other.fuzzy;
		resource = new SomeExternalResource();
		resource->copyContentsFrom(other.resource);
	}

  // move constructor, thats an rvalue reference
	SteeringWheel(SteeringWheel && other) {
		fuzzy = other.fuzzy;
		resource = other.resource;
		other.resource = NULL;
	}

  // destructor, which was coded to expect its organs being harvested
	~SteeringWheel() {
		if (resource != NULL) {
			delete resource;
		}
	}
};


// example of the c way
void doThings(SteeringWheel * derpWheel) {
	// stuff
	// change derpWheel's fuzzy to false
	// now derpWheel dies
}
void makeMeAWheel(SteeringWheel ** steeringWheelPtrPtr) {
	*steeringWheelPtrPtr = new SteeringWheel(true, new SomeExternalResource());
}
int main() {
	SteeringWheel * coolWheel = NULL;
	makeMeAWheel(&coolWheel);
	doThings(coolWheel);
	// myWheel dies here
}



// example of rvalue references / copies being good
void doThings(SteeringWheel derpWheel, function<void(float)> progressCallback) {
	// stuff
	// derpWheel fuzzy is still true
	progressCallback(.1);
	// derpWheel fuzzy is still true good
	// change derpWheel's fuzzy to false
	progressCallback(.2);
	progressCallback(.4);
	// now derpWheel dies
}
SteeringWheel makeMeAWheel() {
	return SteeringWheel(true, new SomeExternalResource());
}
int main() {
	SteeringWheel myWheel = makeMeAWheel();
	// function<void(float)> has: SteeringWheel &
	doThings(std::move(myWheel), [&](float progress){
	  // compiler will complain because myWheel was already doomed
		myWheel.fuzzy = false;
		cout << "Progress: " << progress * 100 << endl;
	});
	// myWheel dies here
}