Shortcut evaluation for hierarchy of in contracts

[Daniel Murphy]

"Timon Gehr" <timon.gehr at gmx.ch> wrote in message 
news:iukvrl$1c1c$1 at digitalmars.com...
>
> Sure, if you remember the Foo/Qux example (Foo is parent, Qux is child, 
> method
> bar(a,b), parent requires a>0 child requires else b>0)
>
> void main(){
>  auto a=new Foo, b=new Qux;
>  a.bar(1,-1);//ok
>  b.bar(1,-1);//ok, child works everywhere parent works
>  //a.bar(-1,1);// not ok
>  //b.bar(-1,-1)// not ok
>  b.bar(-1,1);//ok, child works too if b>0
> }

And it finally clicks!  Thanks for taking the time to explain it to me.
(If only I'd got it sooner, I wouldn't have spent the last two hours 
implementing my behaviour in the compiler)