v1/__numeric/transform_inclusive_scan.h

0001 // -*- C++ -*-
0002 //===----------------------------------------------------------------------===//
0003 //
0004 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0005 // See https://llvm.org/LICENSE.txt for license information.
0006 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0007 //
0008 //===----------------------------------------------------------------------===//
0009
0010 #ifndef _LIBCPP___NUMERIC_TRANSFORM_INCLUSIVE_SCAN_H
0011 #define _LIBCPP___NUMERIC_TRANSFORM_INCLUSIVE_SCAN_H
0012
0013 #include <__config>
0014 #include <__iterator/iterator_traits.h>
0015
0016 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
0017 #  pragma GCC system_header
0018 #endif
0019
0020 _LIBCPP_BEGIN_NAMESPACE_STD
0021
0022 #if _LIBCPP_STD_VER >= 17
0023
0024 template <class _InputIterator, class _OutputIterator, class _Tp, class _BinaryOp, class _UnaryOp>
0025 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator transform_inclusive_scan(
0026     _InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryOp __b, _UnaryOp __u, _Tp __init) {
0027   for (; __first != __last; ++__first, (void)++__result) {
0028     __init    = __b(__init, __u(*__first));
0029     *__result = __init;
0030   }
0031
0032   return __result;
0033 }
0034
0035 template <class _InputIterator, class _OutputIterator, class _BinaryOp, class _UnaryOp>
0036 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator transform_inclusive_scan(
0037     _InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryOp __b, _UnaryOp __u) {
0038   if (__first != __last) {
0039     typename iterator_traits<_InputIterator>::value_type __init = __u(*__first);
0040     *__result++                                                 = __init;
0041     if (++__first != __last)
0042       return std::transform_inclusive_scan(__first, __last, __result, __b, __u, __init);
0043   }
0044
0045   return __result;
0046 }
0047
0048 #endif // _LIBCPP_STD_VER >= 17
0049
0050 _LIBCPP_END_NAMESPACE_STD
0051
0052 #endif // _LIBCPP___NUMERIC_TRANSFORM_INCLUSIVE_SCAN_H