Is assignment of std::array from braced list of values allowed in c++?

In c++ primer, it is mentioned that std::array assignment from braced list of values is not allowed.

Because the size of the right-hand operand might differ from the size of the left-hand operand, the array type does not support assign and it does not allow assignment from a braced list of values.

Below code is given as an example.

  std::array<int, 10> a1 = {0,1,2,3,4,5,6,7,8,9}; 
  std::array<int, 10> a2 = {0}; // elements all have value 0
  a1 = a2; // replaces elements in a1
  a2 = {0}; // error: cannot assign to an array from a braced list

However, when I compile this code with c++11 compiler it works fine. Is this allowed now or am I missing something?