chaining

[Brian]

I want to use a chaining system for easy setting of object attributes, 
which would work great for a single object, unfortunately derived classes 
cannot inherit the chained functions implicitly, whats the best way 
around this?

class Base {
        int x;
        Base foo(int x_) {
                this.x = x_;
                return this;
        }
}

class Derived : Base {
        Derived bar(int y_) {
                return this;
        }
}

// usage:
auto m = (new Derived).foo(10).bar(x); // bar can be accessed through foo