According section 2.13.4 of the standard, a string literal has type "array of n const char". So this should work:

  template <class T>
  void test(T x)
  {
      char const* y;
      T z = y;
  }

  int main()
  {
      test("xxxx");
  }

Although, section 4.2 specifies that a conversion is allowed to a non-const pointer. So this is still allowed:

  char* p = "abc";

But that's deprecated according to Annex D. It's also mentioned in C.1.1.

Daniel