gistfile1.txt

class PropertyTester {
public:
  PropertyTester() 
		: threshold()
		, increment(PropertyTester::incrementAssignSafetyGuard) 
		, isIncrementing(_isIncrementing) {
			_isIncrementing = true;
	}
	Property<int> threshold;
	ConstrainedProperty<int> increment;
	ConstantProperty<bool> isIncrementing;

private:
	static bool incrementAssignSafetyGuard(int a)  {
		return a > 0;
	}
	bool _isIncrementing;
};