// -*- C++ -*-
//===-- numeric_fwd.h --------------------------------------------------===//
//
// 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 __PSTL_numeric_fwd_H
#define __PSTL_numeric_fwd_H

#include <type_traits>
#include <utility>

namespace __pstl
{
namespace internal
{

//------------------------------------------------------------------------
// transform_reduce (version with two binary functions, according to draft N4659)
//------------------------------------------------------------------------

template <class _ForwardIterator1, class _ForwardIterator2, class _Tp, class _BinaryOperation1, class _BinaryOperation2>
_Tp
brick_transform_reduce(_ForwardIterator1, _ForwardIterator1, _ForwardIterator2, _Tp, _BinaryOperation1,
                       _BinaryOperation2,
                       /*__is_vector=*/std::true_type) noexcept;

template <class _ForwardIterator1, class _ForwardIterator2, class _Tp, class _BinaryOperation1, class _BinaryOperation2>
_Tp
brick_transform_reduce(_ForwardIterator1, _ForwardIterator1, _ForwardIterator2, _Tp, _BinaryOperation1,
                       _BinaryOperation2,
                       /*__is_vector=*/std::false_type) noexcept;

template <class _ExecutionPolicy, class _ForwardIterator1, class _ForwardIterator2, class _Tp, class _BinaryOperation1, class _BinaryOperation2,
          class _IsVector>
_Tp
pattern_transform_reduce(_ExecutionPolicy&&, _ForwardIterator1, _ForwardIterator1, _ForwardIterator2, _Tp, _BinaryOperation1,
                         _BinaryOperation2, _IsVector,
                         /*is_parallel=*/std::false_type) noexcept;

#if __PSTL_USE_PAR_POLICIES
template <class _ExecutionPolicy, class _RandomAccessIterator1, class _RandomAccessIterator2, class _Tp, class _BinaryOperation1,
          class _BinaryOperation2, class _IsVector>
_Tp
pattern_transform_reduce(_ExecutionPolicy&&, _RandomAccessIterator1, _RandomAccessIterator1, _RandomAccessIterator2, _Tp, _BinaryOperation1,
                         _BinaryOperation2, _IsVector __is_vector, /*is_parallel=*/std::true_type);
#endif

//------------------------------------------------------------------------
// transform_reduce (version with unary and binary functions)
//------------------------------------------------------------------------

template <class _ForwardIterator, class _Tp, class _UnaryOperation, class _BinaryOperation>
_Tp
brick_transform_reduce(_ForwardIterator, _ForwardIterator, _Tp, _BinaryOperation, _UnaryOperation,
                       /*is_vector=*/std::true_type) noexcept;

template <class _ForwardIterator, class _Tp, class _BinaryOperation, class _UnaryOperation>
_Tp
brick_transform_reduce(_ForwardIterator, _ForwardIterator, _Tp, _BinaryOperation, _UnaryOperation,
                       /*is_vector=*/std::false_type) noexcept;

template <class _ExecutionPolicy, class _ForwardIterator, class _Tp, class _BinaryOperation, class _UnaryOperation, class _IsVector>
_Tp
pattern_transform_reduce(_ExecutionPolicy&&, _ForwardIterator, _ForwardIterator, _Tp, _BinaryOperation, _UnaryOperation, _IsVector,
                         /*is_parallel=*/std::false_type) noexcept;

#if __PSTL_USE_PAR_POLICIES
template <class _ExecutionPolicy, class _ForwardIterator, class _Tp, class _BinaryOperation, class _UnaryOperation, class _IsVector>
_Tp
pattern_transform_reduce(_ExecutionPolicy&&, _ForwardIterator, _ForwardIterator, _Tp, _BinaryOperation, _UnaryOperation, _IsVector,
                         /*is_parallel=*/std::true_type);
#endif

//------------------------------------------------------------------------
// transform_exclusive_scan
//
// walk3 evaluates f(x,y,z) for (x,y,z) drawn from [first1,last1), [first2,...), [first3,...)
//------------------------------------------------------------------------

template <class _ForwardIterator, class _OutputIterator, class _UnaryOperation, class _Tp, class _BinaryOperation>
std::pair<_OutputIterator, _Tp> brick_transform_scan(_ForwardIterator, _ForwardIterator, _OutputIterator,
                                                     _UnaryOperation, _Tp, _BinaryOperation,
                                                     /*Inclusive*/ std::false_type) noexcept;

template <class _ForwardIterator, class _OutputIterator, class _UnaryOperation, class _Tp, class _BinaryOperation>
std::pair<_OutputIterator, _Tp> brick_transform_scan(_ForwardIterator, _ForwardIterator, _OutputIterator,
                                                     _UnaryOperation, _Tp, _BinaryOperation,
                                                     /*Inclusive*/ std::true_type) noexcept;

template <class _ExecutionPolicy, class _ForwardIterator, class _OutputIterator, class _UnaryOperation, class _Tp, class _BinaryOperation,
          class _Inclusive, class _IsVector>
_OutputIterator pattern_transform_scan(_ExecutionPolicy&&, _ForwardIterator, _ForwardIterator, _OutputIterator, _UnaryOperation, _Tp,
                                       _BinaryOperation, _Inclusive, _IsVector,
                                       /*is_parallel=*/std::false_type) noexcept;

#if __PSTL_USE_PAR_POLICIES
template <class _ExecutionPolicy, class _RandomAccessIterator, class _OutputIterator, class _UnaryOperation, class _Tp,
          class _BinaryOperation, class _Inclusive, class _IsVector>
typename std::enable_if<!std::is_floating_point<_Tp>::value, _OutputIterator>::type
pattern_transform_scan(_ExecutionPolicy&&, _RandomAccessIterator, _RandomAccessIterator,
                       _OutputIterator, _UnaryOperation, _Tp, _BinaryOperation,
                       _Inclusive, _IsVector, /*is_parallel=*/std::true_type);
#endif

#if __PSTL_USE_PAR_POLICIES
template <class _ExecutionPolicy, class _RandomAccessIterator, class _OutputIterator, class _UnaryOperation, class _Tp,
          class _BinaryOperation, class _Inclusive, class _IsVector>
typename std::enable_if<std::is_floating_point<_Tp>::value, _OutputIterator>::type
pattern_transform_scan(_ExecutionPolicy&&, _RandomAccessIterator, _RandomAccessIterator,
                       _OutputIterator, _UnaryOperation, _Tp, _BinaryOperation,
                       _Inclusive, _IsVector, /*is_parallel=*/std::true_type);
#endif

//------------------------------------------------------------------------
// adjacent_difference
//------------------------------------------------------------------------

template <class _ForwardIterator, class _OutputIterator, class _BinaryOperation>
_OutputIterator brick_adjacent_difference(_ForwardIterator, _ForwardIterator, _OutputIterator, _BinaryOperation,
                                          /*is_vector*/ std::false_type) noexcept;

template <class _ForwardIterator, class _OutputIterator, class _BinaryOperation>
_OutputIterator brick_adjacent_difference(_ForwardIterator, _ForwardIterator, _OutputIterator, _BinaryOperation,
                                          /*is_vector*/ std::true_type) noexcept;

template <class _ExecutionPolicy, class _ForwardIterator, class _OutputIterator, class _BinaryOperation, class _IsVector>
_OutputIterator pattern_adjacent_difference(_ExecutionPolicy&&, _ForwardIterator, _ForwardIterator, _OutputIterator, _BinaryOperation,
                                            _IsVector, /*is_parallel*/ std::false_type) noexcept;

#if __PSTL_USE_PAR_POLICIES
template <class _ExecutionPolicy, class _ForwardIterator, class _OutputIterator, class _BinaryOperation, class _IsVector>
_OutputIterator pattern_adjacent_difference(_ExecutionPolicy&&, _ForwardIterator, _ForwardIterator, _OutputIterator, _BinaryOperation,
                                            _IsVector, /*is_parallel*/ std::true_type);
#endif

} // namespace internal
} // namespace __pstl
#endif /* __PSTL_numeric_fwd_H */