Rationale (October, 2012):

CWG agreed that this is already permitted by virtue of _N4567_.5.1.1 [expr.prim.general] paragraph 6.

Existing practice appears to be to allow C++03-style aggregate initialization from a parenthesized string literal, e.g.,

  struct S {
    char arr[4];
  } s = {("abc")};

This should be standardized, to allow examples like

  struct S {
    char arr[4];
  };
  void f(S);
  void g() {
    f({("abc")});
  }