// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// 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.
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCUDACXX___FUNCTIONAL_BIND_FRONT_H
#define _LIBCUDACXX___FUNCTIONAL_BIND_FRONT_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

#include <cuda/std/__concepts/concept_macros.h>
#include <cuda/std/__functional/invoke.h>
#include <cuda/std/__functional/perfect_forward.h>
#include <cuda/std/__type_traits/decay.h>
#include <cuda/std/__type_traits/enable_if.h>
#include <cuda/std/__type_traits/is_constructible.h>
#include <cuda/std/__type_traits/is_move_constructible.h>
#include <cuda/std/__type_traits/is_nothrow_constructible.h>
#include <cuda/std/__utility/forward.h>

_LIBCUDACXX_BEGIN_NAMESPACE_STD

struct __bind_front_op
{
  template <class... _Args>
  _LIBCUDACXX_HIDE_FROM_ABI constexpr auto operator()(_Args&&... __args) const
    noexcept(noexcept(_CUDA_VSTD::invoke(_CUDA_VSTD::forward<_Args>(__args)...)))
      -> decltype(_CUDA_VSTD::invoke(_CUDA_VSTD::forward<_Args>(__args)...))
  {
    return _CUDA_VSTD::invoke(_CUDA_VSTD::forward<_Args>(__args)...);
  }
};

template <class _Fn, class... _BoundArgs>
struct __bind_front_t : __perfect_forward<__bind_front_op, _Fn, _BoundArgs...>
{
  _LIBCUDACXX_DELEGATE_CONSTRUCTORS(__bind_front_t, __perfect_forward, __bind_front_op, _Fn, _BoundArgs...);
};

template <class _Fn, class... _Args>
_CCCL_CONCEPT __can_bind_front =
  is_constructible_v<decay_t<_Fn>, _Fn> && is_move_constructible_v<decay_t<_Fn>>
  && (is_constructible_v<decay_t<_Args>, _Args> && ...) && (is_move_constructible_v<decay_t<_Args>> && ...);

_CCCL_TEMPLATE(class _Fn, class... _Args)
_CCCL_REQUIRES(__can_bind_front<_Fn, _Args...>)
_LIBCUDACXX_HIDE_FROM_ABI constexpr auto
bind_front(_Fn&& __f, _Args&&... __args) noexcept(is_nothrow_constructible_v<tuple<decay_t<_Args>...>, _Args&&...>)
{
  return __bind_front_t<decay_t<_Fn>, decay_t<_Args>...>(
    _CUDA_VSTD::forward<_Fn>(__f), _CUDA_VSTD::forward<_Args>(__args)...);
}

_LIBCUDACXX_END_NAMESPACE_STD

#endif // _LIBCUDACXX___FUNCTIONAL_BIND_FRONT_H
