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#ifndef _LIBCUDACXX___MDSPAN_STANDARD_LAYOUT_STATIC_ARRAY_HPP
#define _LIBCUDACXX___MDSPAN_STANDARD_LAYOUT_STATIC_ARRAY_HPP

#include <cuda/std/detail/__config>

#if defined(_CCCL_IMPLICIT_SYSTEM_HEADER_GCC)
#  pragma GCC system_header
#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_CLANG)
#  pragma clang system_header
#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_MSVC)
#  pragma system_header
#endif // no system header

#include <cuda/std/__mdspan/compressed_pair.h>
#include <cuda/std/__mdspan/dynamic_extent.h>
#include <cuda/std/__mdspan/macros.h>
#ifdef _CCCL_HAS_NO_ATTRIBUTE_NO_UNIQUE_ADDRESS
#  include <cuda/std/__mdspan/no_unique_address.h>
#endif // _CCCL_HAS_NO_ATTRIBUTE_NO_UNIQUE_ADDRESS
#include <cuda/std/__type_traits/enable_if.h>
#include <cuda/std/__utility/integer_sequence.h>
#include <cuda/std/array>
#include <cuda/std/cstddef>
#include <cuda/std/span>

_LIBCUDACXX_BEGIN_NAMESPACE_STD

#if _CCCL_STD_VER > 2011

namespace __detail
{

//==============================================================================

struct __construct_psa_from_dynamic_exts_values_tag_t
{};
_LIBCUDACXX_CPO_ACCESSIBILITY __construct_psa_from_dynamic_exts_values_tag_t
  __construct_psa_from_dynamic_exts_values_tag;

struct __construct_psa_from_all_exts_values_tag_t
{};
_LIBCUDACXX_CPO_ACCESSIBILITY __construct_psa_from_all_exts_values_tag_t __construct_psa_from_all_exts_values_tag;

struct __construct_psa_from_all_exts_array_tag_t
{};
template <size_t _Np = 0>
struct __construct_psa_from_dynamic_exts_array_tag_t
{};

//==============================================================================

template <size_t _Ip, class _Tp>
using __repeated_with_idxs = _Tp;

//==============================================================================

#  if __MDSPAN_PRESERVE_STANDARD_LAYOUT

/**
 *  PSA = "partially static array"
 *
 * @tparam _Tp
 * @tparam _ValsSeq
 * @tparam __sentinal
 */
template <class _Tag,
          class _Tp,
          class _static_t,
          class _ValsSeq,
          _static_t __sentinal = static_cast<_static_t>(dynamic_extent),
          class _IdxsSeq       = _CUDA_VSTD::make_index_sequence<_ValsSeq::size()>>
struct __standard_layout_psa;

//==============================================================================
// Static case
template <class _Tag,
          class _Tp,
          class _static_t,
          _static_t __value,
          _static_t... __values_or_sentinals,
          _static_t __sentinal,
          size_t _Idx,
          size_t... _Idxs>
struct __standard_layout_psa<_Tag,
                             _Tp,
                             _static_t,
                             _CUDA_VSTD::integer_sequence<_static_t, __value, __values_or_sentinals...>,
                             __sentinal,
                             _CUDA_VSTD::integer_sequence<size_t, _Idx, _Idxs...>>
#    ifdef _CCCL_HAS_NO_ATTRIBUTE_NO_UNIQUE_ADDRESS
    : private __no_unique_address_emulation<
        __standard_layout_psa<_Tag,
                              _Tp,
                              _static_t,
                              _CUDA_VSTD::integer_sequence<_static_t, __values_or_sentinals...>,
                              __sentinal,
                              _CUDA_VSTD::integer_sequence<size_t, _Idxs...>>>
#    endif
{
  //--------------------------------------------------------------------------

  using __next_t =
    __standard_layout_psa<_Tag,
                          _Tp,
                          _static_t,
                          _CUDA_VSTD::integer_sequence<_static_t, __values_or_sentinals...>,
                          __sentinal,
                          _CUDA_VSTD::integer_sequence<size_t, _Idxs...>>;

#    ifndef _CCCL_HAS_NO_ATTRIBUTE_NO_UNIQUE_ADDRESS
  _CCCL_NO_UNIQUE_ADDRESS __next_t __next_;
#    else
  using __base_t = __no_unique_address_emulation<__next_t>;
#    endif

  __MDSPAN_FORCE_INLINE_FUNCTION constexpr __next_t& __next() noexcept
  {
#    ifndef _CCCL_HAS_NO_ATTRIBUTE_NO_UNIQUE_ADDRESS
    return __next_;
#    else
    return this->__base_t::__ref();
#    endif
  }
  __MDSPAN_FORCE_INLINE_FUNCTION constexpr __next_t const& __next() const noexcept
  {
#    ifndef _CCCL_HAS_NO_ATTRIBUTE_NO_UNIQUE_ADDRESS
    return __next_;
#    else
    return this->__base_t::__ref();
#    endif
  }

  static constexpr auto __size         = sizeof...(_Idxs) + 1;
  static constexpr auto __size_dynamic = __next_t::__size_dynamic;

  //--------------------------------------------------------------------------

  __MDSPAN_INLINE_FUNCTION_DEFAULTED
  constexpr __standard_layout_psa() noexcept = default;
  __MDSPAN_INLINE_FUNCTION_DEFAULTED
  constexpr __standard_layout_psa(__standard_layout_psa const&) noexcept = default;
  __MDSPAN_INLINE_FUNCTION_DEFAULTED
  constexpr __standard_layout_psa(__standard_layout_psa&&) noexcept = default;
  __MDSPAN_INLINE_FUNCTION_DEFAULTED
  __MDSPAN_CONSTEXPR_14_DEFAULTED __standard_layout_psa& operator=(__standard_layout_psa const&) noexcept = default;
  __MDSPAN_INLINE_FUNCTION_DEFAULTED
  __MDSPAN_CONSTEXPR_14_DEFAULTED __standard_layout_psa& operator=(__standard_layout_psa&&) noexcept = default;
  __MDSPAN_INLINE_FUNCTION_DEFAULTED
  ~__standard_layout_psa() noexcept = default;

  //--------------------------------------------------------------------------

  __MDSPAN_INLINE_FUNCTION
  constexpr __standard_layout_psa(__construct_psa_from_all_exts_values_tag_t,
                                  _Tp const& /*__val*/,
                                  __repeated_with_idxs<_Idxs, _Tp> const&... __vals) noexcept
#    ifndef _CCCL_HAS_NO_ATTRIBUTE_NO_UNIQUE_ADDRESS
      : __next_{
#    else
      : __base_t(__base_t{__next_t(
#    endif
        __construct_psa_from_all_exts_values_tag, __vals...
#    ifndef _CCCL_HAS_NO_ATTRIBUTE_NO_UNIQUE_ADDRESS
      }
#    else
        )})
#    endif
  {}

  template <class... _Ts>
  __MDSPAN_INLINE_FUNCTION constexpr __standard_layout_psa(
    __construct_psa_from_dynamic_exts_values_tag_t, _Ts const&... __vals) noexcept
#    ifndef _CCCL_HAS_NO_ATTRIBUTE_NO_UNIQUE_ADDRESS
      : __next_{
#    else
      : __base_t(__base_t{__next_t(
#    endif
        __construct_psa_from_dynamic_exts_values_tag, __vals...
#    ifndef _CCCL_HAS_NO_ATTRIBUTE_NO_UNIQUE_ADDRESS
      }
#    else
        )})
#    endif
  {}

  template <class _Up, size_t _Np>
  __MDSPAN_INLINE_FUNCTION constexpr explicit __standard_layout_psa(array<_Up, _Np> const& __vals) noexcept
#    ifndef _CCCL_HAS_NO_ATTRIBUTE_NO_UNIQUE_ADDRESS
      : __next_{
#    else
      : __base_t(__base_t{__next_t(
#    endif
        __vals
#    ifndef _CCCL_HAS_NO_ATTRIBUTE_NO_UNIQUE_ADDRESS
      }
#    else
        )})
#    endif
  {}

  template <class _Up, size_t _NStatic>
  __MDSPAN_INLINE_FUNCTION constexpr explicit __standard_layout_psa(
    __construct_psa_from_all_exts_array_tag_t const& __tag, array<_Up, _NStatic> const& __vals) noexcept
#    ifndef _CCCL_HAS_NO_ATTRIBUTE_NO_UNIQUE_ADDRESS
      : __next_{
#    else
      : __base_t(__base_t{__next_t(
#    endif
        __tag, __vals
#    ifndef _CCCL_HAS_NO_ATTRIBUTE_NO_UNIQUE_ADDRESS
      }
#    else
        )})
#    endif
  {}

  template <class _Up, size_t _IDynamic, size_t _NDynamic>
  __MDSPAN_INLINE_FUNCTION constexpr explicit __standard_layout_psa(
    __construct_psa_from_dynamic_exts_array_tag_t<_IDynamic> __tag, array<_Up, _NDynamic> const& __vals) noexcept
#    ifndef _CCCL_HAS_NO_ATTRIBUTE_NO_UNIQUE_ADDRESS
      : __next_{
#    else
      : __base_t(__base_t{__next_t(
#    endif
        __tag, __vals
#    ifndef _CCCL_HAS_NO_ATTRIBUTE_NO_UNIQUE_ADDRESS
      }
#    else
        )})
#    endif
  {}

  template <class _Up, size_t _Np>
  __MDSPAN_INLINE_FUNCTION constexpr explicit __standard_layout_psa(_CUDA_VSTD::span<_Up, _Np> const& __vals) noexcept
#    ifndef _CCCL_HAS_NO_ATTRIBUTE_NO_UNIQUE_ADDRESS
      : __next_{
#    else
      : __base_t(__base_t{__next_t(
#    endif
        __vals
#    ifndef _CCCL_HAS_NO_ATTRIBUTE_NO_UNIQUE_ADDRESS
      }
#    else
        )})
#    endif
  {}

  template <class _Up, size_t _NStatic>
  __MDSPAN_INLINE_FUNCTION constexpr explicit __standard_layout_psa(
    __construct_psa_from_all_exts_array_tag_t const& __tag, _CUDA_VSTD::span<_Up, _NStatic> const& __vals) noexcept
#    ifndef _CCCL_HAS_NO_ATTRIBUTE_NO_UNIQUE_ADDRESS
      : __next_{
#    else
      : __base_t(__base_t{__next_t(
#    endif
        __tag, __vals
#    ifndef _CCCL_HAS_NO_ATTRIBUTE_NO_UNIQUE_ADDRESS
      }
#    else
        )})
#    endif
  {}

  template <class _Up, size_t _IDynamic, size_t _NDynamic>
  __MDSPAN_INLINE_FUNCTION constexpr explicit __standard_layout_psa(
    __construct_psa_from_dynamic_exts_array_tag_t<_IDynamic> __tag,
    _CUDA_VSTD::span<_Up, _NDynamic> const& __vals) noexcept
#    ifndef _CCCL_HAS_NO_ATTRIBUTE_NO_UNIQUE_ADDRESS
      : __next_{
#    else
      : __base_t(__base_t{__next_t(
#    endif
        __tag, __vals
#    ifndef _CCCL_HAS_NO_ATTRIBUTE_NO_UNIQUE_ADDRESS
      }
#    else
        )})
#    endif
  {}

  template <class _UTag, class _Up, class _static_U, class _UValsSeq, _static_U __u_sentinal, class _IdxsSeq>
  __MDSPAN_INLINE_FUNCTION constexpr __standard_layout_psa(
    __standard_layout_psa<_UTag, _Up, _static_U, _UValsSeq, __u_sentinal, _IdxsSeq> const& __rhs) noexcept
#    ifndef _CCCL_HAS_NO_ATTRIBUTE_NO_UNIQUE_ADDRESS
      : __next_{
#    else
      : __base_t(__base_t{__next_t(
#    endif
        __rhs.__next()
#    ifndef _CCCL_HAS_NO_ATTRIBUTE_NO_UNIQUE_ADDRESS
      }
#    else
          )})
#    endif
  {}

  //--------------------------------------------------------------------------

  // See https://godbolt.org/z/_KSDNX for a summary-by-example of why this is
  // necessary. We're using inheritance here instead of an alias template
  // because we have to deduce __values_or_sentinals in several places, and
  // alias templates don't permit that in this context.
  __MDSPAN_FORCE_INLINE_FUNCTION
  constexpr __standard_layout_psa const& __enable_psa_conversion() const noexcept
  {
    return *this;
  }

  template <size_t _Ip, _CUDA_VSTD::enable_if_t<_Ip != _Idx, int> = 0>
  __MDSPAN_FORCE_INLINE_FUNCTION constexpr _Tp __get_n() const noexcept
  {
    return __next().template __get_n<_Ip>();
  }
  template <size_t _Ip, _CUDA_VSTD::enable_if_t<_Ip == _Idx, int> = 1>
  __MDSPAN_FORCE_INLINE_FUNCTION constexpr _Tp __get_n() const noexcept
  {
    return __value;
  }
  template <size_t _Ip, _CUDA_VSTD::enable_if_t<_Ip != _Idx, int> = 0>
  __MDSPAN_FORCE_INLINE_FUNCTION constexpr void __set_n(_Tp const& __rhs) noexcept
  {
    __next().__set_value(__rhs);
  }
  template <size_t _Ip, _CUDA_VSTD::enable_if_t<_Ip == _Idx, int> = 1>
  __MDSPAN_FORCE_INLINE_FUNCTION constexpr void __set_n(_Tp const&) noexcept
  {
    // Don't assert here because that would break constexpr. This better
    // not change anything, though
  }
  template <size_t _Ip, _CUDA_VSTD::enable_if_t<_Ip == _Idx, _static_t> = __sentinal>
  __MDSPAN_FORCE_INLINE_FUNCTION static constexpr _static_t __get_static_n() noexcept
  {
    return __value;
  }
  template <size_t _Ip, _CUDA_VSTD::enable_if_t<_Ip != _Idx, _static_t> __default = __sentinal>
  __MDSPAN_FORCE_INLINE_FUNCTION static constexpr _static_t __get_static_n() noexcept
  {
    return __next_t::template __get_static_n<_Ip, __default>();
  }
  __MDSPAN_FORCE_INLINE_FUNCTION constexpr _Tp __get(size_t __n) const noexcept
  {
    return __value * (_Tp(_Idx == __n)) + __next().__get(__n);
  }

  //--------------------------------------------------------------------------
};

//==============================================================================

// Dynamic case, __next_t may or may not be empty
template <class _Tag,
          class _Tp,
          class _static_t,
          _static_t __sentinal,
          _static_t... __values_or_sentinals,
          size_t _Idx,
          size_t... _Idxs>
struct __standard_layout_psa<_Tag,
                             _Tp,
                             _static_t,
                             _CUDA_VSTD::integer_sequence<_static_t, __sentinal, __values_or_sentinals...>,
                             __sentinal,
                             _CUDA_VSTD::integer_sequence<size_t, _Idx, _Idxs...>>
{
  //--------------------------------------------------------------------------

  using __next_t =
    __standard_layout_psa<_Tag,
                          _Tp,
                          _static_t,
                          _CUDA_VSTD::integer_sequence<_static_t, __values_or_sentinals...>,
                          __sentinal,
                          _CUDA_VSTD::integer_sequence<size_t, _Idxs...>>;

  using __value_pair_t = __compressed_pair<_Tp, __next_t>;
  __value_pair_t __value_pair;
  __MDSPAN_FORCE_INLINE_FUNCTION constexpr __next_t& __next() noexcept
  {
    return __value_pair.__second();
  }
  __MDSPAN_FORCE_INLINE_FUNCTION constexpr __next_t const& __next() const noexcept
  {
    return __value_pair.__second();
  }

  static constexpr auto __size         = sizeof...(_Idxs) + 1;
  static constexpr auto __size_dynamic = 1 + __next_t::__size_dynamic;

  //--------------------------------------------------------------------------

  __MDSPAN_INLINE_FUNCTION_DEFAULTED
  constexpr __standard_layout_psa() noexcept = default;
  __MDSPAN_INLINE_FUNCTION_DEFAULTED
  constexpr __standard_layout_psa(__standard_layout_psa const&) noexcept = default;
  __MDSPAN_INLINE_FUNCTION_DEFAULTED
  constexpr __standard_layout_psa(__standard_layout_psa&&) noexcept = default;
  __MDSPAN_INLINE_FUNCTION_DEFAULTED
  __MDSPAN_CONSTEXPR_14_DEFAULTED __standard_layout_psa& operator=(__standard_layout_psa const&) noexcept = default;
  __MDSPAN_INLINE_FUNCTION_DEFAULTED
  __MDSPAN_CONSTEXPR_14_DEFAULTED __standard_layout_psa& operator=(__standard_layout_psa&&) noexcept = default;
  __MDSPAN_INLINE_FUNCTION_DEFAULTED
  ~__standard_layout_psa() noexcept = default;

  //--------------------------------------------------------------------------

  __MDSPAN_INLINE_FUNCTION
  constexpr __standard_layout_psa(__construct_psa_from_all_exts_values_tag_t,
                                  _Tp const& __val,
                                  __repeated_with_idxs<_Idxs, _Tp> const&... __vals) noexcept
      : __value_pair(__val, __next_t(__construct_psa_from_all_exts_values_tag, __vals...))
  {}

  template <class... _Ts>
  __MDSPAN_INLINE_FUNCTION constexpr __standard_layout_psa(
    __construct_psa_from_dynamic_exts_values_tag_t, _Tp const& __val, _Ts const&... __vals) noexcept
      : __value_pair(__val, __next_t(__construct_psa_from_dynamic_exts_values_tag, __vals...))
  {}

  template <class _Up, size_t _Np>
  __MDSPAN_INLINE_FUNCTION constexpr explicit __standard_layout_psa(array<_Up, _Np> const& __vals) noexcept
      : __value_pair(_CUDA_VSTD::get<_Idx>(__vals), __vals)
  {}

  template <class _Up, size_t _NStatic>
  __MDSPAN_INLINE_FUNCTION constexpr explicit __standard_layout_psa(
    __construct_psa_from_all_exts_array_tag_t __tag, array<_Up, _NStatic> const& __vals) noexcept
      : __value_pair(_CUDA_VSTD::get<_Idx>(__vals), __next_t(__tag, __vals))
  {}

  template <class _Up, size_t _IDynamic, size_t _NDynamic>
  __MDSPAN_INLINE_FUNCTION constexpr explicit __standard_layout_psa(
    __construct_psa_from_dynamic_exts_array_tag_t<_IDynamic>, array<_Up, _NDynamic> const& __vals) noexcept
      : __value_pair(_CUDA_VSTD::get<_IDynamic>(__vals),
                     __next_t(__construct_psa_from_dynamic_exts_array_tag_t<_IDynamic + 1>{}, __vals))
  {}

  template <class _Up, size_t _Np>
  __MDSPAN_INLINE_FUNCTION constexpr explicit __standard_layout_psa(_CUDA_VSTD::span<_Up, _Np> const& __vals) noexcept
      : __value_pair(__vals[_Idx], __vals)
  {}

  template <class _Up, size_t _NStatic>
  __MDSPAN_INLINE_FUNCTION constexpr explicit __standard_layout_psa(
    __construct_psa_from_all_exts_array_tag_t __tag, _CUDA_VSTD::span<_Up, _NStatic> const& __vals) noexcept
      : __value_pair(__vals[_Idx], __next_t(__tag, __vals))
  {}

  template <class _Up, size_t _IDynamic, size_t _NDynamic>
  __MDSPAN_INLINE_FUNCTION constexpr explicit __standard_layout_psa(
    __construct_psa_from_dynamic_exts_array_tag_t<_IDynamic>, _CUDA_VSTD::span<_Up, _NDynamic> const& __vals) noexcept
      : __value_pair(__vals[_IDynamic],
                     __next_t(__construct_psa_from_dynamic_exts_array_tag_t<_IDynamic + 1>{}, __vals))
  {}

  template <class _UTag, class _Up, class _static_U, class _UValsSeq, _static_U __u_sentinal, class _UIdxsSeq>
  __MDSPAN_INLINE_FUNCTION constexpr __standard_layout_psa(
    __standard_layout_psa<_UTag, _Up, _static_U, _UValsSeq, __u_sentinal, _UIdxsSeq> const& __rhs) noexcept
      : __value_pair(__rhs.template __get_n<_Idx>(), __rhs.__next())
  {}

  //--------------------------------------------------------------------------

  // See comment in the previous partial specialization for why this is
  // necessary.  Or just trust me that it's messy.
  __MDSPAN_FORCE_INLINE_FUNCTION
  constexpr __standard_layout_psa const& __enable_psa_conversion() const noexcept
  {
    return *this;
  }

  template <size_t _Ip, _CUDA_VSTD::enable_if_t<_Ip != _Idx, int> = 0>
  __MDSPAN_FORCE_INLINE_FUNCTION constexpr _Tp __get_n() const noexcept
  {
    return __next().template __get_n<_Ip>();
  }
  template <size_t _Ip, _CUDA_VSTD::enable_if_t<_Ip == _Idx, int> = 1>
  __MDSPAN_FORCE_INLINE_FUNCTION constexpr _Tp __get_n() const noexcept
  {
    return __value_pair.__first();
  }
  template <size_t _Ip, _CUDA_VSTD::enable_if_t<_Ip != _Idx, int> = 0>
  __MDSPAN_FORCE_INLINE_FUNCTION constexpr void __set_n(_Tp const& __rhs) noexcept
  {
    __next().__set_value(__rhs);
  }
  template <size_t _Ip, _CUDA_VSTD::enable_if_t<_Ip == _Idx, int> = 1>
  __MDSPAN_FORCE_INLINE_FUNCTION constexpr void __set_n(_Tp const& __rhs) noexcept
  {
    __value_pair.__first() = __rhs;
  }
  template <size_t _Ip, _CUDA_VSTD::enable_if_t<_Ip == _Idx, _static_t> __default = __sentinal>
  __MDSPAN_FORCE_INLINE_FUNCTION static constexpr _static_t __get_static_n() noexcept
  {
    return __default;
  }
  template <size_t _Ip, _CUDA_VSTD::enable_if_t<_Ip != _Idx, _static_t> __default = __sentinal>
  __MDSPAN_FORCE_INLINE_FUNCTION static constexpr _static_t __get_static_n() noexcept
  {
    return __next_t::template __get_static_n<_Ip, __default>();
  }
  __MDSPAN_FORCE_INLINE_FUNCTION constexpr _Tp __get(size_t __n) const noexcept
  {
    return __value_pair.__first() * (_Tp(_Idx == __n)) + __next().__get(__n);
  }

  //--------------------------------------------------------------------------
};

// empty/terminal case
template <class _Tag, class _Tp, class _static_t, _static_t __sentinal>
struct __standard_layout_psa<_Tag,
                             _Tp,
                             _static_t,
                             _CUDA_VSTD::integer_sequence<_static_t>,
                             __sentinal,
                             _CUDA_VSTD::integer_sequence<size_t>>
{
  //--------------------------------------------------------------------------

  static constexpr auto __size         = 0;
  static constexpr auto __size_dynamic = 0;

  //--------------------------------------------------------------------------

  __MDSPAN_INLINE_FUNCTION_DEFAULTED
  constexpr __standard_layout_psa() noexcept = default;
  __MDSPAN_INLINE_FUNCTION_DEFAULTED
  constexpr __standard_layout_psa(__standard_layout_psa const&) noexcept = default;
  __MDSPAN_INLINE_FUNCTION_DEFAULTED
  constexpr __standard_layout_psa(__standard_layout_psa&&) noexcept = default;
  __MDSPAN_INLINE_FUNCTION_DEFAULTED
  __MDSPAN_CONSTEXPR_14_DEFAULTED __standard_layout_psa& operator=(__standard_layout_psa const&) noexcept = default;
  __MDSPAN_INLINE_FUNCTION_DEFAULTED
  __MDSPAN_CONSTEXPR_14_DEFAULTED __standard_layout_psa& operator=(__standard_layout_psa&&) noexcept = default;
  __MDSPAN_INLINE_FUNCTION_DEFAULTED
  ~__standard_layout_psa() noexcept = default;

  __MDSPAN_INLINE_FUNCTION
  constexpr __standard_layout_psa(__construct_psa_from_all_exts_values_tag_t) noexcept {}

  template <class... _Ts>
  __MDSPAN_INLINE_FUNCTION constexpr __standard_layout_psa(__construct_psa_from_dynamic_exts_values_tag_t) noexcept
  {}

  template <class _Up, size_t _Np>
  __MDSPAN_INLINE_FUNCTION constexpr explicit __standard_layout_psa(array<_Up, _Np> const&) noexcept
  {}

  template <class _Up, size_t _NStatic>
  __MDSPAN_INLINE_FUNCTION constexpr explicit __standard_layout_psa(
    __construct_psa_from_all_exts_array_tag_t, array<_Up, _NStatic> const&) noexcept
  {}

  template <class _Up, size_t _IDynamic, size_t _NDynamic>
  __MDSPAN_INLINE_FUNCTION constexpr explicit __standard_layout_psa(
    __construct_psa_from_dynamic_exts_array_tag_t<_IDynamic>, array<_Up, _NDynamic> const&) noexcept
  {}

  template <class _Up, size_t _Np>
  __MDSPAN_INLINE_FUNCTION constexpr explicit __standard_layout_psa(_CUDA_VSTD::span<_Up, _Np> const&) noexcept
  {}

  template <class _Up, size_t _NStatic>
  __MDSPAN_INLINE_FUNCTION constexpr explicit __standard_layout_psa(
    __construct_psa_from_all_exts_array_tag_t, _CUDA_VSTD::span<_Up, _NStatic> const&) noexcept
  {}

  template <class _Up, size_t _IDynamic, size_t _NDynamic>
  __MDSPAN_INLINE_FUNCTION constexpr explicit __standard_layout_psa(
    __construct_psa_from_dynamic_exts_array_tag_t<_IDynamic>, _CUDA_VSTD::span<_Up, _NDynamic> const&) noexcept
  {}

  template <class _UTag, class _Up, class _static_U, class _UValsSeq, _static_U __u_sentinal, class _UIdxsSeq>
  __MDSPAN_INLINE_FUNCTION constexpr __standard_layout_psa(
    __standard_layout_psa<_UTag, _Up, _static_U, _UValsSeq, __u_sentinal, _UIdxsSeq> const&) noexcept
  {}

  // See comment in the previous partial specialization for why this is
  // necessary.  Or just trust me that it's messy.
  __MDSPAN_FORCE_INLINE_FUNCTION
  constexpr __standard_layout_psa const& __enable_psa_conversion() const noexcept
  {
    return *this;
  }

  __MDSPAN_FORCE_INLINE_FUNCTION constexpr _Tp __get(size_t /*n*/) const noexcept
  {
    return 0;
  }
};

// Same thing, but with a disambiguator so that same-base issues doesn't cause
// a loss of standard-layout-ness.
template <class _Tag, class T, class _static_t, _static_t... __values_or_sentinals>
struct __partially_static_sizes_tagged
    : __standard_layout_psa<_Tag, T, _static_t, _CUDA_VSTD::integer_sequence<_static_t, __values_or_sentinals...>>
{
  using __tag_t = _Tag;
  using __psa_impl_t =
    __standard_layout_psa<_Tag, T, _static_t, _CUDA_VSTD::integer_sequence<_static_t, __values_or_sentinals...>>;
#    if defined(_CCCL_COMPILER_NVRTC) || defined(_CCCL_CUDACC_BELOW_11_3)
  template <class... _Args, __enable_if_t<_CCCL_TRAIT(is_constructible, __psa_impl_t, _Args...), int> = 0>
  __MDSPAN_FORCE_INLINE_FUNCTION constexpr __partially_static_sizes_tagged(_Args&&... __args) noexcept(
    noexcept(__psa_impl_t(_CUDA_VSTD::declval<_Args>()...)))
      : __psa_impl_t(_CUDA_VSTD::forward<_Args>(__args)...)
  {}
#    else // ^^^ _CCCL_COMPILER_NVRTC || nvcc < 11.3 ^^^ / vvv !_CCCL_COMPILER_NVRTC || nvcc >= 11.3 vvv
  using __psa_impl_t::__psa_impl_t;
#    endif // !_CCCL_COMPILER_NVRTC || nvcc >= 11.3
#    ifdef __MDSPAN_DEFAULTED_CONSTRUCTORS_INHERITANCE_WORKAROUND
  __MDSPAN_INLINE_FUNCTION
#    endif
  constexpr __partially_static_sizes_tagged() noexcept
#    ifdef __MDSPAN_DEFAULTED_CONSTRUCTORS_INHERITANCE_WORKAROUND
      : __psa_impl_t(){}
#    else
    = default;
#    endif
      // This line seems to be unstable under clang-format
      // clang-format off
      __MDSPAN_INLINE_FUNCTION_DEFAULTED
      constexpr __partially_static_sizes_tagged(__partially_static_sizes_tagged const&) noexcept = default;
  //clang-format on
  __MDSPAN_INLINE_FUNCTION_DEFAULTED
  constexpr __partially_static_sizes_tagged(__partially_static_sizes_tagged&&) noexcept = default;
  __MDSPAN_INLINE_FUNCTION_DEFAULTED
  __MDSPAN_CONSTEXPR_14_DEFAULTED __partially_static_sizes_tagged&
  operator=(__partially_static_sizes_tagged const&) noexcept = default;
  __MDSPAN_INLINE_FUNCTION_DEFAULTED
  __MDSPAN_CONSTEXPR_14_DEFAULTED __partially_static_sizes_tagged&
  operator=(__partially_static_sizes_tagged&&) noexcept = default;
  __MDSPAN_INLINE_FUNCTION_DEFAULTED
  ~__partially_static_sizes_tagged() noexcept = default;

  template <class _UTag>
  __MDSPAN_FORCE_INLINE_FUNCTION constexpr explicit __partially_static_sizes_tagged(
    __partially_static_sizes_tagged<_UTag, T, _static_t, __values_or_sentinals...> const& __vals) noexcept
      : __psa_impl_t(__vals.__enable_psa_conversion())
  {}
};

struct __no_tag
{};
template <class T, class _static_t, _static_t... __values_or_sentinals>
struct __partially_static_sizes : __partially_static_sizes_tagged<__no_tag, T, _static_t, __values_or_sentinals...>
{
private:
  using __base_t = __partially_static_sizes_tagged<__no_tag, T, _static_t, __values_or_sentinals...>;
  template <class _UTag>
  __MDSPAN_FORCE_INLINE_FUNCTION constexpr __partially_static_sizes(
    __partially_static_sizes_tagged<_UTag, T, _static_t, __values_or_sentinals...>&& __vals) noexcept
      : __base_t(_CUDA_VSTD::move(__vals))
  {}

public:
#    if defined(_CCCL_COMPILER_NVRTC) || defined(_CCCL_CUDACC_BELOW_11_3)
  template <class... _Args, __enable_if_t<_CCCL_TRAIT(is_constructible, __base_t, _Args...), int> = 0>
  __MDSPAN_FORCE_INLINE_FUNCTION constexpr __partially_static_sizes(_Args&&... __args) noexcept(
    noexcept(__base_t(_CUDA_VSTD::declval<_Args>()...)))
      : __base_t(_CUDA_VSTD::forward<_Args>(__args)...)
  {}
#    else // ^^^ _CCCL_COMPILER_NVRTC || nvcc < 11.3 ^^^ / vvv !_CCCL_COMPILER_NVRTC || nvcc >= 11.3 vvv
  using __base_t::__base_t;
#    endif // !_CCCL_COMPILER_NVRTC || nvcc >= 11.3

#    ifdef __MDSPAN_DEFAULTED_CONSTRUCTORS_INHERITANCE_WORKAROUND
  __MDSPAN_INLINE_FUNCTION
  constexpr __partially_static_sizes() noexcept
      : __base_t()
  {}
#    endif
  template <class _UTag>
  __MDSPAN_FORCE_INLINE_FUNCTION constexpr __partially_static_sizes_tagged<_UTag, T, _static_t, __values_or_sentinals...>
  __with_tag() const noexcept
  {
    return __partially_static_sizes_tagged<_UTag, T, _static_t, __values_or_sentinals...>(*this);
  }
};

#  endif // __MDSPAN_PRESERVE_STATIC_LAYOUT

} // end namespace __detail

#endif // _CCCL_STD_VER > 2011

_LIBCUDACXX_END_NAMESPACE_STD

#endif // _LIBCUDACXX___MDSPAN_STANDARD_LAYOUT_STATIC_ARRAY_HPP