libcxx/include/__numeric/transform_reduce.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_REDUCE_H
  11 #define _LIBCPP___NUMERIC_TRANSFORM_REDUCE_H
  12
  13 #include <__config>
  14 #include <__functional/operations.h>
  15 #include <__utility/move.h>
  16
  17 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  18 #  pragma GCC system_header
  19 #endif
  20
  21 _LIBCPP_PUSH_MACROS
  22 #include <__undef_macros>
  23
  24 _LIBCPP_BEGIN_NAMESPACE_STD
  25
  26 #if _LIBCPP_STD_VER >= 17
  27 template <class _InputIterator, class _Tp, class _BinaryOp, class _UnaryOp>
  28 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Tp
  29 transform_reduce(_InputIterator __first, _InputIterator __last, _Tp __init, _BinaryOp __b, _UnaryOp __u) {
  30   for (; __first != __last; ++__first)
  31     __init = __b(std::move(__init), __u(*__first));
  32   return __init;
  33 }
  34
  35 template <class _InputIterator1, class _InputIterator2, class _Tp, class _BinaryOp1, class _BinaryOp2>
  36 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Tp transform_reduce(
  37     _InputIterator1 __first1,
  38     _InputIterator1 __last1,
  39     _InputIterator2 __first2,
  40     _Tp __init,
  41     _BinaryOp1 __b1,
  42     _BinaryOp2 __b2) {
  43   for (; __first1 != __last1; ++__first1, (void)++__first2)
  44     __init = __b1(std::move(__init), __b2(*__first1, *__first2));
  45   return __init;
  46 }
  47
  48 template <class _InputIterator1, class _InputIterator2, class _Tp>
  49 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Tp
  50 transform_reduce(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _Tp __init) {
  51   return std::transform_reduce(__first1, __last1, __first2, std::move(__init), std::plus<>(), std::multiplies<>());
  52 }
  53 #endif
  54
  55 _LIBCPP_END_NAMESPACE_STD
  56
  57 _LIBCPP_POP_MACROS
  58
  59 #endif // _LIBCPP___NUMERIC_TRANSFORM_REDUCE_H