Readonly field for class type

[Andrey via Digitalmars-d-learn]

Hello, is there way to declare read only field for class type 
with ability to call inner non constant methods? i.e.:

class A {
    int value = 12;
    void updateValue() {
        value = 13;
    }
}
class B {
    const A a;

    this() {
        a = new A();
        a.updateValue();  // error: mutable method is not 
callable using const object
    }
}