C++程序  |  22行  |  577 B

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
//                     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.
//
//===----------------------------------------------------------------------===//

// UNSUPPORTED: c++98, c++03, c++11, c++14

// <variant>

// constexpr size_t variant_npos = -1;

#include <variant>

int main() {
  static_assert(std::variant_npos == static_cast<std::size_t>(-1), "");
}