// -*- 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
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP___NUMERIC_TRANSFORM_INCLUSIVE_SCAN_H
#define _LIBCPP___NUMERIC_TRANSFORM_INCLUSIVE_SCAN_H

#include <__config>
#include <__iterator/iterator_traits.h>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#  pragma GCC system_header
#endif

_LIBCPP_BEGIN_NAMESPACE_STD

#if _LIBCPP_STD_VER >= 17

template <class _InputIterator, class _OutputIterator, class _Tp, class _BinaryOp, class _UnaryOp>
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20
_OutputIterator
transform_inclusive_scan(_InputIterator __first, _InputIterator __last,
                           _OutputIterator __result, _BinaryOp __b, _UnaryOp __u, _Tp __init)
{
    for (; __first != __last; ++__first, (void) ++__result) {
        __init = __b(__init, __u(*__first));
        *__result = __init;
        }

    return __result;
}

template <class _InputIterator, class _OutputIterator, class _BinaryOp, class _UnaryOp>
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20
_OutputIterator
transform_inclusive_scan(_InputIterator __first, _InputIterator __last,
                               _OutputIterator __result, _BinaryOp __b, _UnaryOp __u)
{
    if (__first != __last) {
        typename iterator_traits<_InputIterator>::value_type __init = __u(*__first);
        *__result++ = __init;
        if (++__first != __last)
            return _VSTD::transform_inclusive_scan(__first, __last, __result, __b, __u, __init);
    }

    return __result;
}

#endif // _LIBCPP_STD_VER >= 17

_LIBCPP_END_NAMESPACE_STD

#endif // _LIBCPP___NUMERIC_TRANSFORM_INCLUSIVE_SCAN_H