small sample of a hard to parse C++ file

torture.cpp

#define PASTE(x,y) x##y
#define COLON :

// this class is: evil
class H;
typedef class H HH;
/*
	class NotHere {};
*/
namespace
{
	class I { };
	class I;
	namespace ns1
	{
		class I { };
		PASTE(cl,ass) A : I
		{
		};
		namespace ns2
		{
			typedef ns1::A I;
			struct B PASTE(COL,ON) private I {
				typedef B T;
				class H *h;
				class C : A { };
			};
			struct B b;
		}
	}

	template<typename T, class U=ns1::ns2::B> struct D : ns1::ns2::I
	{
		class E : U::T { };
	};
	class F : public D<F> { };
}

union G { };
class H : D<D<G>, H> { };

int main()
{
	ns1::A a;
	ns1::ns2::B b;
	F f;
	G g;
}