Assign a value to a std::reference_wrapper

How can we assign a value to an item wrapped by std::reference_wrapper?

int a[] = {0, 1, 2, 3, 4};

std::vector <std::reference_wrapper<int>> v(a, a+5);

v[0] = 1234;  // Error, can not assign value !

Accoring to error, direct assignment is deleted:

error: use of deleted function 'std::reference_wrapper<_Tp>::reference_wrapper(_Tp&&) [with _Tp = int]'