3 * Copyright (c) 2014, Facebook, Inc.
6 * This source code is licensed under the BSD-style license found in the
7 * LICENSE file in the "hack" directory of this source tree. An additional grant
8 * of patent rights can be found in the PATENTS file in the same directory.
12 interface FormatString
<T
> { }
15 function f(FormatString
<X
> $fs, ...) : void
{
18 function _(string $s) {