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//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// <optional>
// A program that necessitates the instantiation of template optional for
// (possibly cv-qualified) null_opt_t is ill-formed.
#include <experimental/optional>
int main()
{
#if _LIBCPP_STD_VER > 11
using std::experimental::optional;
using std::experimental::nullopt_t;
using std::experimental::nullopt;
optional<nullopt_t> opt;
#else
#error
#endif // _LIBCPP_STD_VER > 11
}
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