//===----------------------------------------------------------------------===//
//
// 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: c++03, c++11, c++14

// template<class T>
// concept contiguous_iterator;

#include <cuda/std/iterator>

#include "test_iterators.h"

static_assert(!cuda::std::contiguous_iterator<cpp17_input_iterator<int*>>);
static_assert(!cuda::std::contiguous_iterator<cpp20_input_iterator<int*>>);
static_assert(!cuda::std::contiguous_iterator<forward_iterator<int*>>);
static_assert(!cuda::std::contiguous_iterator<bidirectional_iterator<int*>>);
static_assert(!cuda::std::contiguous_iterator<random_access_iterator<int*>>);
static_assert(cuda::std::contiguous_iterator<contiguous_iterator<int*>>);

static_assert(cuda::std::contiguous_iterator<int*>);
static_assert(cuda::std::contiguous_iterator<int const*>);
static_assert(cuda::std::contiguous_iterator<int volatile*>);
static_assert(cuda::std::contiguous_iterator<int const volatile*>);

struct simple_contiguous_iterator {
    typedef cuda::std::contiguous_iterator_tag  iterator_category;
    typedef int                                 value_type;
    typedef int                                 element_type;
    typedef cuda::std::ptrdiff_t                difference_type;
    typedef int*                                pointer;
    typedef int&                                reference;
    typedef simple_contiguous_iterator          self;

    __host__ __device__ simple_contiguous_iterator();

    __host__ __device__ reference operator*() const;
    __host__ __device__ pointer operator->() const;
#ifndef TEST_HAS_NO_SPACESHIP_OPERATOR
    auto operator<=>(const self&) const = default;
#else
    __host__ __device__ friend bool operator==(const self&, const self&) { return true; };
    __host__ __device__ friend bool operator!=(const self&, const self&) { return false; };
    __host__ __device__ friend bool operator<(const self&, const self&)  { return true; };
    __host__ __device__ friend bool operator<=(const self&, const self&)  { return true; };
    __host__ __device__ friend bool operator>(const self&, const self&)  { return true; };
    __host__ __device__ friend bool operator>=(const self&, const self&)  { return true; };
#endif

    __host__ __device__ self& operator++();
    __host__ __device__ self operator++(int);

    __host__ __device__ self& operator--();
    __host__ __device__ self operator--(int);

    __host__ __device__ self& operator+=(difference_type n);
    __host__ __device__ self operator+(difference_type n) const;
    __host__ __device__ friend self operator+(difference_type n, self x);

    __host__ __device__ self& operator-=(difference_type n);
    __host__ __device__ self operator-(difference_type n) const;
    __host__ __device__ difference_type operator-(const self& n) const;

    __host__ __device__ reference operator[](difference_type n) const;
};

static_assert(cuda::std::random_access_iterator<simple_contiguous_iterator>);
static_assert(cuda::std::contiguous_iterator<simple_contiguous_iterator>);

struct mismatch_value_iter_ref_t {
    typedef cuda::std::contiguous_iterator_tag  iterator_category;
    typedef short                               value_type;
#if TEST_STD_VER < 20
    typedef short                               element_type;
#endif
    typedef cuda::std::ptrdiff_t                difference_type;
    typedef int*                                pointer;
    typedef int&                                reference;
    typedef mismatch_value_iter_ref_t           self;

    __host__ __device__ mismatch_value_iter_ref_t();

    __host__ __device__ reference operator*() const;
    __host__ __device__ pointer operator->() const;
#ifndef TEST_HAS_NO_SPACESHIP_OPERATOR
    auto operator<=>(const self&) const = default;
#else
    __host__ __device__ friend bool operator==(const self&, const self&) { return true; };
    __host__ __device__ friend bool operator!=(const self&, const self&) { return false; };
    __host__ __device__ friend bool operator<(const self&, const self&)  { return true; };
    __host__ __device__ friend bool operator<=(const self&, const self&)  { return true; };
    __host__ __device__ friend bool operator>(const self&, const self&)  { return true; };
    __host__ __device__ friend bool operator>=(const self&, const self&)  { return true; };
#endif

    __host__ __device__ self& operator++();
    __host__ __device__ self operator++(int);

    __host__ __device__ self& operator--();
    __host__ __device__ self operator--(int);

    __host__ __device__ self& operator+=(difference_type n);
    __host__ __device__ self operator+(difference_type n) const;
    __host__ __device__ friend self operator+(difference_type n, self x);

    __host__ __device__ self& operator-=(difference_type n);
    __host__ __device__ self operator-(difference_type n) const;
    __host__ __device__ difference_type operator-(const self& n) const;

    __host__ __device__ reference operator[](difference_type n) const;
};

static_assert(cuda::std::random_access_iterator<mismatch_value_iter_ref_t>);
static_assert(!cuda::std::contiguous_iterator<mismatch_value_iter_ref_t>);

struct wrong_iter_reference_t {
    typedef cuda::std::contiguous_iterator_tag    iterator_category;
    typedef short                           value_type;
    typedef short                           element_type;
    typedef cuda::std::ptrdiff_t            difference_type;
    typedef short*                          pointer;
    typedef int&                            reference;
    typedef wrong_iter_reference_t          self;

    __host__ __device__ wrong_iter_reference_t();

    __host__ __device__ reference operator*() const;
    __host__ __device__ pointer operator->() const;
#ifndef TEST_HAS_NO_SPACESHIP_OPERATOR
    auto operator<=>(const self&) const = default;
#else
    __host__ __device__ friend bool operator==(const self&, const self&) { return true; };
    __host__ __device__ friend bool operator!=(const self&, const self&) { return false; };
    __host__ __device__ friend bool operator<(const self&, const self&)  { return true; };
    __host__ __device__ friend bool operator<=(const self&, const self&)  { return true; };
    __host__ __device__ friend bool operator>(const self&, const self&)  { return true; };
    __host__ __device__ friend bool operator>=(const self&, const self&)  { return true; };
#endif

    __host__ __device__ self& operator++();
    __host__ __device__ self operator++(int);

    __host__ __device__ self& operator--();
    __host__ __device__ self operator--(int);

    __host__ __device__ self& operator+=(difference_type n);
    __host__ __device__ self operator+(difference_type n) const;
    __host__ __device__ friend self operator+(difference_type n, self x);

    __host__ __device__ self& operator-=(difference_type n);
    __host__ __device__ self operator-(difference_type n) const;
    __host__ __device__ difference_type operator-(const self& n) const;

    __host__ __device__ reference operator[](difference_type n) const;
};

static_assert(cuda::std::random_access_iterator<wrong_iter_reference_t>);
static_assert(!cuda::std::contiguous_iterator<wrong_iter_reference_t>);

struct to_address_wrong_return_type {
    typedef cuda::std::contiguous_iterator_tag  iterator_category;
    typedef int                                 value_type;
    typedef int                                 element_type;
    typedef cuda::std::ptrdiff_t                difference_type;
    typedef int*                                pointer;
    typedef int&                                reference;
    typedef to_address_wrong_return_type        self;

    __host__ __device__ to_address_wrong_return_type();

    __host__ __device__ reference operator*() const;
    __host__ __device__ pointer operator->() const;
#ifndef TEST_HAS_NO_SPACESHIP_OPERATOR
    auto operator<=>(const self&) const = default;
#else
    __host__ __device__ friend bool operator==(const self&, const self&) { return true; };
    __host__ __device__ friend bool operator!=(const self&, const self&) { return false; };
    __host__ __device__ friend bool operator<(const self&, const self&)  { return true; };
    __host__ __device__ friend bool operator<=(const self&, const self&)  { return true; };
    __host__ __device__ friend bool operator>(const self&, const self&)  { return true; };
    __host__ __device__ friend bool operator>=(const self&, const self&)  { return true; };
#endif

    __host__ __device__ self& operator++();
    __host__ __device__ self operator++(int);

    __host__ __device__ self& operator--();
    __host__ __device__ self operator--(int);

    __host__ __device__ self& operator+=(difference_type n);
    __host__ __device__ self operator+(difference_type n) const;
    __host__ __device__ friend self operator+(difference_type n, self x);

    __host__ __device__ self& operator-=(difference_type n);
    __host__ __device__ self operator-(difference_type n) const;
    __host__ __device__ difference_type operator-(const self& n) const;

    __host__ __device__ reference operator[](difference_type n) const;
};

template<>
struct cuda::std::pointer_traits<to_address_wrong_return_type> {
  typedef void element_type;
  __host__ __device__ static void *to_address(to_address_wrong_return_type const&);
};

static_assert(cuda::std::random_access_iterator<to_address_wrong_return_type>);
static_assert(!cuda::std::contiguous_iterator<to_address_wrong_return_type>);

template<class>
struct template_and_no_element_type {
    typedef cuda::std::contiguous_iterator_tag    iterator_category;
    typedef int                             value_type;
    typedef cuda::std::ptrdiff_t                  difference_type;
    typedef int*                            pointer;
    typedef int&                            reference;
    typedef template_and_no_element_type    self;

    __host__ __device__ template_and_no_element_type();

    __host__ __device__ reference operator*() const;
    __host__ __device__ pointer operator->() const;
#ifndef TEST_HAS_NO_SPACESHIP_OPERATOR
    auto operator<=>(const self&) const = default;
#else
    __host__ __device__ friend bool operator==(const self&, const self&) { return true; };
    __host__ __device__ friend bool operator!=(const self&, const self&) { return false; };
    __host__ __device__ friend bool operator<(const self&, const self&)  { return true; };
    __host__ __device__ friend bool operator<=(const self&, const self&)  { return true; };
    __host__ __device__ friend bool operator>(const self&, const self&)  { return true; };
    __host__ __device__ friend bool operator>=(const self&, const self&)  { return true; };
#endif

    __host__ __device__ self& operator++();
    __host__ __device__ self operator++(int);

    __host__ __device__ self& operator--();
    __host__ __device__ self operator--(int);

    __host__ __device__ self& operator+=(difference_type n);
    __host__ __device__ self operator+(difference_type n) const;
    __host__ __device__ friend self operator+(difference_type, self) { return self{}; }

    __host__ __device__ self& operator-=(difference_type n);
    __host__ __device__ self operator-(difference_type n) const;
    __host__ __device__ difference_type operator-(const self& n) const;

    __host__ __device__ reference operator[](difference_type n) const;
};

// Template param is used instead of element_type.
static_assert(cuda::std::random_access_iterator<template_and_no_element_type<int>>);
static_assert(cuda::std::contiguous_iterator<template_and_no_element_type<int>>);

template <bool DisableArrow, bool DisableToAddress>
struct no_operator_arrow {
    typedef cuda::std::contiguous_iterator_tag    iterator_category;
    typedef int                             value_type;
    typedef int                             element_type;
    typedef cuda::std::ptrdiff_t                  difference_type;
    typedef int*                            pointer;
    typedef int&                            reference;
    typedef no_operator_arrow               self;

    __host__ __device__ no_operator_arrow();

    __host__ __device__ reference operator*() const;
#ifndef TEST_HAS_NO_SPACESHIP_OPERATOR
    __host__ __device__ pointer operator->() const requires (!DisableArrow);
    auto operator<=>(const self&) const = default;
#else
    template<bool B = DisableArrow, cuda::std::enable_if_t<!B, int> = 0>
    __host__ __device__ pointer operator->() const;
    __host__ __device__ friend bool operator==(const self&, const self&) { return true; };
    __host__ __device__ friend bool operator!=(const self&, const self&) { return false; };
    __host__ __device__ friend bool operator<(const self&, const self&)  { return true; };
    __host__ __device__ friend bool operator<=(const self&, const self&)  { return true; };
    __host__ __device__ friend bool operator>(const self&, const self&)  { return true; };
    __host__ __device__ friend bool operator>=(const self&, const self&)  { return true; };
#endif

    __host__ __device__ self& operator++();
    __host__ __device__ self operator++(int);

    __host__ __device__ self& operator--();
    __host__ __device__ self operator--(int);

    __host__ __device__ self& operator+=(difference_type n);
    __host__ __device__ self operator+(difference_type n) const;
    __host__ __device__ friend self operator+(difference_type, self) { return self{}; }

    __host__ __device__ self& operator-=(difference_type n);
    __host__ __device__ self operator-(difference_type n) const;
    __host__ __device__ difference_type operator-(const self& n) const;

    __host__ __device__ reference operator[](difference_type n) const;
};

template<>
struct cuda::std::pointer_traits<no_operator_arrow</*DisableArrow=*/true, /*DisableToAddress=*/false>> {
  __host__ __device__ static constexpr int *to_address(const no_operator_arrow<true, false>&);
};

static_assert(cuda::std::contiguous_iterator<no_operator_arrow</*DisableArrow=*/false, /*DisableToAddress=*/true>>);
static_assert(!cuda::std::contiguous_iterator<no_operator_arrow</*DisableArrow=*/true, /*DisableToAddress=*/true>>);
static_assert(cuda::std::contiguous_iterator<no_operator_arrow</*DisableArrow=*/true, /*DisableToAddress=*/false>>);

int main(int, char**)
{
  return 0;
}
