llvm-project/clang/test/CodeGenCXX/2006-09-12-OpaqueStructCrash.cpp

// RUN: %clang_cc1 -emit-llvm -o - %s

struct A {
   virtual ~A();
};

template <typename Ty>
struct B : public A {
   ~B () { delete [] val; }
private:
     Ty* val;
};

template <typename Ty>
struct C : public A {
   C ();
   ~C ();
};

template <typename Ty>
struct D : public A {
     D () {}
   private:
     B<C<Ty> > blocks;
};

template class D<double>;