src/third_party/llvm-project/libcxx/test/std/experimental/language.support/support.coroutines/coroutine.handle/coroutine.handle.con/assign.pass.cpp

// -*- 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

// <experimental/coroutine>

// template <class Promise = void>
// struct coroutine_handle;

// coroutine_handle& operator=(nullptr_t) noexcept

#include <experimental/coroutine>
#include <type_traits>
#include <cassert>

namespace coro = std::experimental;

template <class C>
void do_test() {
  int dummy = 42;
  void* dummy_h = &dummy;
  {
    C c; ((void)c);
    static_assert(std::is_nothrow_assignable<C&, std::nullptr_t>::value, "");
    static_assert(!std::is_assignable<C&, void*>::value, "");
  }
  {
    C c = C::from_address(dummy_h);
    assert(c.address() == &dummy);
    c = nullptr;
    assert(c.address() == nullptr);
    c = nullptr;
    assert(c.address() == nullptr);
  }
  {
    C c;
    C& cr = (c = nullptr);
    assert(&c == &cr);
  }
}

int main()
{
  do_test<coro::coroutine_handle<>>();
  do_test<coro::coroutine_handle<int>>();
}