//===----------------------------------------------------------------------===//
//
// 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 _LIBCUDACXX___FUNCTIONAL_UNARY_FUNCTION_H
#define _LIBCUDACXX___FUNCTIONAL_UNARY_FUNCTION_H

#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

_LIBCUDACXX_BEGIN_NAMESPACE_STD

#if _CCCL_STD_VER <= 2014 || defined(_LIBCUDACXX_ENABLE_CXX17_REMOVED_UNARY_BINARY_FUNCTION)

template <class _Arg, class _Result>
struct _LIBCUDACXX_TEMPLATE_VIS _LIBCUDACXX_DEPRECATED_IN_CXX11 unary_function
{
  typedef _Arg argument_type;
  typedef _Result result_type;
};

#endif // _CCCL_STD_VER <= 2014

template <class _Arg, class _Result>
struct __unary_function_keep_layout_base
{
#if _CCCL_STD_VER <= 2017 || defined(_LIBCUDACXX_ENABLE_CXX20_REMOVED_BINDER_TYPEDEFS)
  using argument_type _LIBCUDACXX_DEPRECATED_IN_CXX17 = _Arg;
  using result_type _LIBCUDACXX_DEPRECATED_IN_CXX17   = _Result;
#endif
};

#if _CCCL_STD_VER <= 2014 || defined(_LIBCUDACXX_ENABLE_CXX17_REMOVED_UNARY_BINARY_FUNCTION)

_CCCL_SUPPRESS_DEPRECATED_PUSH
template <class _Arg, class _Result>
using __unary_function = unary_function<_Arg, _Result>;
_CCCL_SUPPRESS_DEPRECATED_POP

#else
template <class _Arg, class _Result>
using __unary_function = __unary_function_keep_layout_base<_Arg, _Result>;
#endif

_LIBCUDACXX_END_NAMESPACE_STD

#endif // _LIBCUDACXX___FUNCTIONAL_UNARY_FUNCTION_H