text: //===----------------------------------------------------------------------===//
  //
  // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  // See https://llvm.org/LICENSE.txt for license information.
  // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  //
  //===----------------------------------------------------------------------===//
  //
  // UNSUPPORTED: libcpp-has-no-threads, c++98, c++03
  
  // <mutex>
  
  // template <class Mutex> class unique_lock;
  
  // unique_lock& operator=(unique_lock&& u);
  
  #include <mutex>
  #include <cassert>
  #include "nasty_containers.hpp"
  
  #include "test_macros.h"
  
  int main(int, char**)
  {
      {
      typedef std::mutex M;
      M m0;
      M m1;
      std::unique_lock<M> lk0(m0);
      std::unique_lock<M> lk1(m1);
      lk1 = std::move(lk0);
      assert(lk1.mutex() == std::addressof(m0));
      assert(lk1.owns_lock() == true);
      assert(lk0.mutex() == nullptr);
      assert(lk0.owns_lock() == false);
      }
      {
      typedef nasty_mutex M;
      M m0;
      M m1;
      std::unique_lock<M> lk0(m0);
      std::unique_lock<M> lk1(m1);
      lk1 = std::move(lk0);
      assert(lk1.mutex() == std::addressof(m0));
      assert(lk1.owns_lock() == true);
      assert(lk0.mutex() == nullptr);
      assert(lk0.owns_lock() == false);
      }
  
    return 0;
  }
  