llvm-project/libcxx/include/__numeric/transform_exclusive_scan.h

// -*- 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_EXCLUSIVE_SCAN_H
#define _LIBCPP___NUMERIC_TRANSFORM_EXCLUSIVE_SCAN_H

#include <__config>

#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_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator transform_exclusive_scan(
    _InputIterator __first, _InputIterator __last, _OutputIterator __result, _Tp __init, _BinaryOp __b, _UnaryOp __u) {
  if (__first != __last) {
    _Tp __saved = __init;
    do {
      __init    = __b(__init, __u(*__first));
      *__result = __saved;
      __saved   = __init;
      ++__result;
    } while (++__first != __last);
  }
  return __result;
}

#endif // _LIBCPP_STD_VER >= 17

_LIBCPP_END_NAMESPACE_STD

#endif // _LIBCPP___NUMERIC_TRANSFORM_EXCLUSIVE_SCAN_H