This code crashes the compiler:

class E(uint N) { }

class Boom
{
   typedef E!(5) ET;
public:
   ET foo() const  // Badness here!
   { return x[3]; }

   ET[int] x;
}

void main()
{
   auto b = new Boom();
   b.foo();
}

Technically, it's invalid, because I'm returning a mutable member reference from a const member function.  However, the error message is to crash the compiler.  Note that if you replace ET with a builtin or a non-template class, it correctly emits the expected error.  Not sure why the template type blows it up, but it does.

Dave