libcxx/include/__numeric/transform_inclusive_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_INCLUSIVE_SCAN_H
  11 #define _LIBCPP___NUMERIC_TRANSFORM_INCLUSIVE_SCAN_H
  12
  13 #include <__config>
  14 #include <__iterator/iterator_traits.h>
  15
  16 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  17 #  pragma GCC system_header
  18 #endif
  19
  20 _LIBCPP_BEGIN_NAMESPACE_STD
  21
  22 #if _LIBCPP_STD_VER > 14
  23
  24 template <class _InputIterator, class _OutputIterator, class _Tp, class _BinaryOp, class _UnaryOp>
  25 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
  26 _OutputIterator
  27 transform_inclusive_scan(_InputIterator __first, _InputIterator __last,
  28                            _OutputIterator __result, _BinaryOp __b, _UnaryOp __u, _Tp __init)
  29 {
  30     for (; __first != __last; ++__first, (void) ++__result) {
  31         __init = __b(__init, __u(*__first));
  32         *__result = __init;
  33         }
  34
  35     return __result;
  36 }
  37
  38 template <class _InputIterator, class _OutputIterator, class _BinaryOp, class _UnaryOp>
  39 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
  40 _OutputIterator
  41 transform_inclusive_scan(_InputIterator __first, _InputIterator __last,
  42                                _OutputIterator __result, _BinaryOp __b, _UnaryOp __u)
  43 {
  44     if (__first != __last) {
  45         typename iterator_traits<_InputIterator>::value_type __init = __u(*__first);
  46         *__result++ = __init;
  47         if (++__first != __last)
  48             return _VSTD::transform_inclusive_scan(__first, __last, __result, __b, __u, __init);
  49     }
  50
  51     return __result;
  52 }
  53
  54 #endif // _LIBCPP_STD_VER > 14
  55
  56 _LIBCPP_END_NAMESPACE_STD
  57
  58 #endif // _LIBCPP___NUMERIC_TRANSFORM_INCLUSIVE_SCAN_H