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 >= 17
  23
  24 template <class _InputIterator, class _OutputIterator, class _Tp, class _BinaryOp, class _UnaryOp>
  25 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator transform_inclusive_scan(
  26     _InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryOp __b, _UnaryOp __u, _Tp __init) {
  27   for (; __first != __last; ++__first, (void)++__result) {
  28     __init    = __b(__init, __u(*__first));
  29     *__result = __init;
  30   }
  31
  32   return __result;
  33 }
  34
  35 template <class _InputIterator, class _OutputIterator, class _BinaryOp, class _UnaryOp>
  36 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator transform_inclusive_scan(
  37     _InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryOp __b, _UnaryOp __u) {
  38   if (__first != __last) {
  39     typename iterator_traits<_InputIterator>::value_type __init = __u(*__first);
  40     *__result++                                                 = __init;
  41     if (++__first != __last)
  42       return std::transform_inclusive_scan(__first, __last, __result, __b, __u, __init);
  43   }
  44
  45   return __result;
  46 }
  47
  48 #endif // _LIBCPP_STD_VER >= 17
  49
  50 _LIBCPP_END_NAMESPACE_STD
  51
  52 #endif // _LIBCPP___NUMERIC_TRANSFORM_INCLUSIVE_SCAN_H