No, that typedef problem is what C++ inherited from C, which is easily handled if you have a Linear-bounded TM (actually, a long time ago I think if our parser

No, that typedef problem is what C++ inherited from C, which is easily handled if you have a Linear-bounded TM (actually, a long time ago I think if our parser is able to interpret different state by different extra memory (like symbol table and AST), it is actually mimicking a restricted TM...until I learnt about some details of Chomsky Hierarchy) What I mean is something like "Foo<Bar<Baz>>", the ">>" part can be a little bit challenging because we don't know if this is a right shift or not without context C++ is also Turing Complete that its template system can implement boundless recursion and infinitely expand on its own without termination...essentially it means it may not even halt. That's why template metaprogramming is a (hard and horrible) thing...it's a sublanguage that uses C++ syntax and generates C++ code making the parsing even more non-deterministic.