//===----------------------------------------------------------------------===//
//
// 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
// SPDX-FileCopyrightText: Copyright (c) 2023 NVIDIA CORPORATION & AFFILIATES.
//
//===----------------------------------------------------------------------===//

// UNSUPPORTED: gcc-6

// <cuda/std/optional>

// template <class T> void swap(optional<T>& x, optional<T>& y)
//     noexcept(noexcept(x.swap(y)));

#include <cuda/std/cassert>
#include <cuda/std/optional>
#include <cuda/std/type_traits>

#include "archetypes.h"
#include "test_macros.h"

using cuda::std::optional;

class X
{
  int i_;

public:
  STATIC_MEMBER_VAR(dtor_called, unsigned)
  __host__ __device__ X(int i)
      : i_(i)
  {}
  X(X&& x)          = default;
  X& operator=(X&&) = default;
  __host__ __device__ ~X()
  {
    ++dtor_called();
  }

  __host__ __device__ friend bool operator==(const X& x, const X& y)
  {
    return x.i_ == y.i_;
  }
};

class Y
{
  int i_;

public:
  STATIC_MEMBER_VAR(dtor_called, unsigned)
  __host__ __device__ Y(int i)
      : i_(i)
  {}
  Y(Y&&) = default;
  __host__ __device__ ~Y()
  {
    ++dtor_called();
  }

  __host__ __device__ friend constexpr bool operator==(const Y& x, const Y& y)
  {
    return x.i_ == y.i_;
  }
  __host__ __device__ friend void swap(Y& x, Y& y)
  {
    cuda::std::swap(x.i_, y.i_);
  }
};

class TerminatesOnMoveAssignmentAndSwap
{
public:
  __host__ __device__ TerminatesOnMoveAssignmentAndSwap(int) {}
  __host__ __device__ TerminatesOnMoveAssignmentAndSwap(TerminatesOnMoveAssignmentAndSwap&&)
  {
    cuda::std::terminate();
  }

  __host__ __device__ friend void swap(TerminatesOnMoveAssignmentAndSwap&, TerminatesOnMoveAssignmentAndSwap&)
  {
    cuda::std::terminate();
  }
};

#ifndef TEST_HAS_NO_EXCEPTIONS
class Z
{
  int i_;

public:
  Z(int i)
      : i_(i)
  {}
  Z(Z&&)
  {
    TEST_THROW(7);
  }

  friend constexpr bool operator==(const Z& x, const Z& y)
  {
    return x.i_ == y.i_;
  }
  friend void swap(Z&, Z&)
  {
    TEST_THROW(6);
  }
};

void test_exceptions()
{
  {
    optional<Z> opt1;
    opt1.emplace(1);
    optional<Z> opt2{};
    static_assert(noexcept(swap(opt1, opt2)) == false, "");
    assert(static_cast<bool>(opt1) == true);
    assert(*opt1 == 1);
    assert(static_cast<bool>(opt2) == false);
    try
    {
      swap(opt1, opt2);
      assert(false);
    }
    catch (int i)
    {
      assert(i == 7);
    }
    assert(static_cast<bool>(opt1) == true);
    assert(*opt1 == 1);
    assert(static_cast<bool>(opt2) == false);
  }
  {
    optional<Z> opt1;
    optional<Z> opt2{};
    opt2.emplace(2);
    static_assert(noexcept(swap(opt1, opt2)) == false, "");
    assert(static_cast<bool>(opt1) == false);
    assert(static_cast<bool>(opt2) == true);
    assert(*opt2 == 2);
    try
    {
      swap(opt1, opt2);
      assert(false);
    }
    catch (int i)
    {
      assert(i == 7);
    }
    assert(static_cast<bool>(opt1) == false);
    assert(static_cast<bool>(opt2) == true);
    assert(*opt2 == 2);
  }
  {
    optional<Z> opt1;
    opt1.emplace(1);
    optional<Z> opt2{};
    opt2.emplace(2);
    static_assert(noexcept(swap(opt1, opt2)) == false, "");
    assert(static_cast<bool>(opt1) == true);
    assert(*opt1 == 1);
    assert(static_cast<bool>(opt2) == true);
    assert(*opt2 == 2);
    try
    {
      swap(opt1, opt2);
      assert(false);
    }
    catch (int i)
    {
      assert(i == 6);
    }
    assert(static_cast<bool>(opt1) == true);
    assert(*opt1 == 1);
    assert(static_cast<bool>(opt2) == true);
    assert(*opt2 == 2);
  }
}
#endif // !TEST_HAS_NO_EXCEPTIONS

struct NonSwappable
{
  NonSwappable(NonSwappable const&) = delete;
};
__host__ __device__ // what in the world, nvrtc?!
  void
  swap(NonSwappable&, NonSwappable&) = delete;

__host__ __device__ void test_swap_sfinae()
{
  using cuda::std::optional;
  {
    using T = TestTypes::TestType;
    static_assert(cuda::std::is_swappable_v<optional<T>>, "");
  }
  {
    using T = TestTypes::MoveOnly;
    static_assert(cuda::std::is_swappable_v<optional<T>>, "");
  }
  {
    using T = TestTypes::Copyable;
    static_assert(cuda::std::is_swappable_v<optional<T>>, "");
  }
  {
    using T = TestTypes::NoCtors;
    static_assert(!cuda::std::is_swappable_v<optional<T>>, "");
  }
  {
    using T = NonSwappable;
    static_assert(!cuda::std::is_swappable_v<optional<T>>, "");
  }
  {
    // Even though CopyOnly has deleted move operations, those operations
    // cause optional<CopyOnly> to have implicitly deleted move operations
    // that decay into copies.
    using T   = TestTypes::CopyOnly;
    using Opt = optional<T>;
    T::reset();
    Opt L(101), R(42);
    T::reset_constructors();
    cuda::std::swap(L, R);
    assert(L->value == 42);
    assert(R->value == 101);
    assert(T::copy_constructed() == 1);
    assert(T::constructed() == T::copy_constructed());
    assert(T::assigned() == 2);
    assert(T::assigned() == T::copy_assigned());
  }
}

int main(int, char**)
{
  test_swap_sfinae();
  {
    optional<int> opt1;
    optional<int> opt2{};
    static_assert(noexcept(swap(opt1, opt2)) == true, "");
    assert(static_cast<bool>(opt1) == false);
    assert(static_cast<bool>(opt2) == false);
    swap(opt1, opt2);
    assert(static_cast<bool>(opt1) == false);
    assert(static_cast<bool>(opt2) == false);
  }
  {
    optional<int> opt1(1);
    optional<int> opt2{};
    static_assert(noexcept(swap(opt1, opt2)) == true, "");
    assert(static_cast<bool>(opt1) == true);
    assert(*opt1 == 1);
    assert(static_cast<bool>(opt2) == false);
    swap(opt1, opt2);
    assert(static_cast<bool>(opt1) == false);
    assert(static_cast<bool>(opt2) == true);
    assert(*opt2 == 1);
  }
  {
    optional<int> opt1;
    optional<int> opt2(2);
    static_assert(noexcept(swap(opt1, opt2)) == true, "");
    assert(static_cast<bool>(opt1) == false);
    assert(static_cast<bool>(opt2) == true);
    assert(*opt2 == 2);
    swap(opt1, opt2);
    assert(static_cast<bool>(opt1) == true);
    assert(*opt1 == 2);
    assert(static_cast<bool>(opt2) == false);
  }
  {
    optional<int> opt1(1);
    optional<int> opt2(2);
    static_assert(noexcept(swap(opt1, opt2)) == true, "");
    assert(static_cast<bool>(opt1) == true);
    assert(*opt1 == 1);
    assert(static_cast<bool>(opt2) == true);
    assert(*opt2 == 2);
    swap(opt1, opt2);
    assert(static_cast<bool>(opt1) == true);
    assert(*opt1 == 2);
    assert(static_cast<bool>(opt2) == true);
    assert(*opt2 == 1);
  }
  {
    optional<X> opt1;
    optional<X> opt2{};
    static_assert(noexcept(swap(opt1, opt2)) == true, "");
    assert(static_cast<bool>(opt1) == false);
    assert(static_cast<bool>(opt2) == false);
    swap(opt1, opt2);
    assert(static_cast<bool>(opt1) == false);
    assert(static_cast<bool>(opt2) == false);
    assert(X::dtor_called() == 0);
  }
  {
    optional<X> opt1(1);
    optional<X> opt2{};
    static_assert(noexcept(swap(opt1, opt2)) == true, "");
    assert(static_cast<bool>(opt1) == true);
    assert(*opt1 == 1);
    assert(static_cast<bool>(opt2) == false);
    X::dtor_called() = 0;
    swap(opt1, opt2);
    assert(X::dtor_called() == 1);
    assert(static_cast<bool>(opt1) == false);
    assert(static_cast<bool>(opt2) == true);
    assert(*opt2 == 1);
  }
  {
    optional<X> opt1;
    optional<X> opt2(2);
    static_assert(noexcept(swap(opt1, opt2)) == true, "");
    assert(static_cast<bool>(opt1) == false);
    assert(static_cast<bool>(opt2) == true);
    assert(*opt2 == 2);
    X::dtor_called() = 0;
    swap(opt1, opt2);
    assert(X::dtor_called() == 1);
    assert(static_cast<bool>(opt1) == true);
    assert(*opt1 == 2);
    assert(static_cast<bool>(opt2) == false);
  }
  {
    optional<X> opt1(1);
    optional<X> opt2(2);
    static_assert(noexcept(swap(opt1, opt2)) == true, "");
    assert(static_cast<bool>(opt1) == true);
    assert(*opt1 == 1);
    assert(static_cast<bool>(opt2) == true);
    assert(*opt2 == 2);
    X::dtor_called() = 0;
    swap(opt1, opt2);
    assert(X::dtor_called() == 1); // from inside cuda::std::swap
    assert(static_cast<bool>(opt1) == true);
    assert(*opt1 == 2);
    assert(static_cast<bool>(opt2) == true);
    assert(*opt2 == 1);
  }
  {
    optional<Y> opt1;
    optional<Y> opt2{};
    static_assert(noexcept(swap(opt1, opt2)) == false, "");
    assert(static_cast<bool>(opt1) == false);
    assert(static_cast<bool>(opt2) == false);
    swap(opt1, opt2);
    assert(static_cast<bool>(opt1) == false);
    assert(static_cast<bool>(opt2) == false);
    assert(Y::dtor_called() == 0);
  }
  {
    optional<Y> opt1(1);
    optional<Y> opt2{};
    static_assert(noexcept(swap(opt1, opt2)) == false, "");
    assert(static_cast<bool>(opt1) == true);
    assert(*opt1 == 1);
    assert(static_cast<bool>(opt2) == false);
    Y::dtor_called() = 0;
    swap(opt1, opt2);
    assert(Y::dtor_called() == 1);
    assert(static_cast<bool>(opt1) == false);
    assert(static_cast<bool>(opt2) == true);
    assert(*opt2 == 1);
  }
  {
    optional<Y> opt1;
    optional<Y> opt2(2);
    static_assert(noexcept(swap(opt1, opt2)) == false, "");
    assert(static_cast<bool>(opt1) == false);
    assert(static_cast<bool>(opt2) == true);
    assert(*opt2 == 2);
    Y::dtor_called() = 0;
    swap(opt1, opt2);
    assert(Y::dtor_called() == 1);
    assert(static_cast<bool>(opt1) == true);
    assert(*opt1 == 2);
    assert(static_cast<bool>(opt2) == false);
  }
  {
    optional<Y> opt1(1);
    optional<Y> opt2(2);
    static_assert(noexcept(swap(opt1, opt2)) == false, "");
    assert(static_cast<bool>(opt1) == true);
    assert(*opt1 == 1);
    assert(static_cast<bool>(opt2) == true);
    assert(*opt2 == 2);
    Y::dtor_called() = 0;
    swap(opt1, opt2);
    assert(Y::dtor_called() == 0);
    assert(static_cast<bool>(opt1) == true);
    assert(*opt1 == 2);
    assert(static_cast<bool>(opt2) == true);
    assert(*opt2 == 1);
  }
  {
    optional<TerminatesOnMoveAssignmentAndSwap> opt1;
    optional<TerminatesOnMoveAssignmentAndSwap> opt2{};
    static_assert(noexcept(swap(opt1, opt2)) == false, "");
    assert(static_cast<bool>(opt1) == false);
    assert(static_cast<bool>(opt2) == false);
    swap(opt1, opt2);
    assert(static_cast<bool>(opt1) == false);
    assert(static_cast<bool>(opt2) == false);
  }

  {
    int value       = 42;
    int other_value = 1337;
    optional<int&> opt1(value);
    optional<int&> opt2(other_value);
    static_assert(noexcept(swap(opt1, opt2)), "");
    assert(opt1.has_value());
    assert(*opt1 == value);
    assert(opt2.has_value());
    assert(*opt2 == other_value);
    assert(cuda::std::addressof(value) == opt1.operator->());
    assert(cuda::std::addressof(other_value) == opt2.operator->());
    swap(opt1, opt2);
    assert(opt1.has_value());
    assert(*opt1 == other_value);
    assert(opt2.has_value());
    assert(*opt2 == value);
    assert(cuda::std::addressof(value) == opt2.operator->());
    assert(cuda::std::addressof(other_value) == opt1.operator->());
  }

#ifndef TEST_HAS_NO_EXCEPTIONS
  NV_IF_TARGET(NV_IS_HOST, (test_exceptions();))
#endif // !TEST_HAS_NO_EXCEPTIONS

  return 0;
}