Thread: One template question

Code:

template <typename T, typename CONT /*= std::vector*/ > 
struct Stack{
    CONT elem;
};

The above code compiles fine as it should be If I just uncomment the std::vector one it fires compilation errors saying

Code:

error: expected type-specifier
error: expected '>'

But I don't find any syntactic or symantic error in the above code. can anybody please point it out.