What is the difference between 'typedef' and 'using' in C++11?

Question

I know that in C++11 we can now use using to write type alias, like typedefs:

typedef int MyInt;

Is, from what I

Answer 1

They are essentially the same but using provides alias templates which is quite useful. One good example I could find is as follows:

namespace std {
 template using add_const_t = typename add_const::type;
}

So, we can use std::add_const_t instead of typename std::add_const::type