libcxx/include/__numeric/transform_exclusive_scan.h

   1 // -*- C++ -*-
   2 //===----------------------------------------------------------------------===//
   3 //
   4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   5 // See https://llvm.org/LICENSE.txt for license information.
   6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #ifndef _LIBCPP___NUMERIC_TRANSFORM_EXCLUSIVE_SCAN_H
  11 #define _LIBCPP___NUMERIC_TRANSFORM_EXCLUSIVE_SCAN_H
  12
  13 #include <__config>
  14
  15 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  16 #  pragma GCC system_header
  17 #endif
  18
  19 _LIBCPP_BEGIN_NAMESPACE_STD
  20
  21 #if _LIBCPP_STD_VER >= 17
  22
  23 template <class _InputIterator, class _OutputIterator, class _Tp,
  24           class _BinaryOp, class _UnaryOp>
  25 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20
  26 _OutputIterator
  27 transform_exclusive_scan(_InputIterator __first, _InputIterator __last,
  28                            _OutputIterator __result, _Tp __init,
  29                            _BinaryOp __b, _UnaryOp __u)
  30 {
  31     if (__first != __last)
  32     {
  33         _Tp __saved = __init;
  34         do
  35         {
  36             __init = __b(__init, __u(*__first));
  37             *__result = __saved;
  38             __saved = __init;
  39             ++__result;
  40         } while (++__first != __last);
  41     }
  42     return __result;
  43 }
  44
  45 #endif // _LIBCPP_STD_VER >= 17
  46
  47 _LIBCPP_END_NAMESPACE_STD
  48
  49 #endif // _LIBCPP___NUMERIC_TRANSFORM_EXCLUSIVE_SCAN_H