How to group similar member functions from different classes?

[Marc Schütz via Digitalmars-d-learn]

Untested:

// foo.d
import a, b;
mixin template Foos {
     static if(is(typeof(this) == A))
     void foo() { /* implementation for A */ }
     static if(is(typeof(this) == B))
     void foo() { /* implementation for B */ }
}

// a.d
import foo;
class A {
     mixin Foos;
}

// b.d
import foo;
class B {
     mixin Foos;
}

You must not have static constructors in any of these modules 
because you'd likely get problems with circular initialization.