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
  //
  //===----------------------------------------------------------------------===//
  
  #ifndef _LIBCPP___COMPARE_COMPARE_STRONG_ORDER_FALLBACK
  #define _LIBCPP___COMPARE_COMPARE_STRONG_ORDER_FALLBACK
  
  #include <__compare/ordering.h>
  #include <__compare/strong_order.h>
  #include <__config>
  #include <__utility/forward.h>
  #include <__utility/priority_tag.h>
  #include <type_traits>
  
  #ifndef _LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER
  #pragma GCC system_header
  #endif
  
  _LIBCPP_BEGIN_NAMESPACE_STD
  
  #if !defined(_LIBCPP_HAS_NO_CONCEPTS)
  
  // [cmp.alg]
  namespace __compare_strong_order_fallback {
      struct __fn {
          template<class _Tp, class _Up>
              requires is_same_v<decay_t<_Tp>, decay_t<_Up>>
          _LIBCPP_HIDE_FROM_ABI static constexpr auto
          __go(_Tp&& __t, _Up&& __u, __priority_tag<1>)
              noexcept(noexcept(_VSTD::strong_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u))))
              -> decltype(      _VSTD::strong_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u)))
              { return          _VSTD::strong_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u)); }
  
          template<class _Tp, class _Up>
              requires is_same_v<decay_t<_Tp>, decay_t<_Up>>
          _LIBCPP_HIDE_FROM_ABI static constexpr auto
          __go(_Tp&& __t, _Up&& __u, __priority_tag<0>)
              noexcept(noexcept(_VSTD::forward<_Tp>(__t) == _VSTD::forward<_Up>(__u) ? strong_ordering::equal :
                                _VSTD::forward<_Tp>(__t) < _VSTD::forward<_Up>(__u) ? strong_ordering::less :
                                strong_ordering::greater))
              -> decltype(      _VSTD::forward<_Tp>(__t) == _VSTD::forward<_Up>(__u) ? strong_ordering::equal :
                                _VSTD::forward<_Tp>(__t) < _VSTD::forward<_Up>(__u) ? strong_ordering::less :
                                strong_ordering::greater)
          {
              return            _VSTD::forward<_Tp>(__t) == _VSTD::forward<_Up>(__u) ? strong_ordering::equal :
                                _VSTD::forward<_Tp>(__t) < _VSTD::forward<_Up>(__u) ? strong_ordering::less :
                                strong_ordering::greater;
          }
  
          template<class _Tp, class _Up>
          _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Tp&& __t, _Up&& __u) const
              noexcept(noexcept(__go(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u), __priority_tag<1>())))
              -> decltype(      __go(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u), __priority_tag<1>()))
              { return          __go(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u), __priority_tag<1>()); }
      };
  } // namespace __compare_strong_order_fallback
  
  inline namespace __cpo {
      inline constexpr auto compare_strong_order_fallback = __compare_strong_order_fallback::__fn{};
  } // namespace __cpo
  
  #endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
  
  _LIBCPP_END_NAMESPACE_STD
  
  #endif // _LIBCPP___COMPARE_COMPARE_STRONG_ORDER_FALLBACK
  