libcxx/include/__numeric/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_REDUCE_H
  11 #define _LIBCPP___NUMERIC_REDUCE_H
  12
  13 #include <__config>
  14 #include <__functional/operations.h>
  15 #include <__iterator/iterator_traits.h>
  16 #include <__utility/move.h>
  17
  18 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  19 #  pragma GCC system_header
  20 #endif
  21
  22 _LIBCPP_BEGIN_NAMESPACE_STD
  23
  24 #if _LIBCPP_STD_VER >= 17
  25 template <class _InputIterator, class _Tp, class _BinaryOp>
  26 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20 _Tp reduce(_InputIterator __first, _InputIterator __last,
  27                                                                    _Tp __init, _BinaryOp __b) {
  28   for (; __first != __last; ++__first)
  29     __init = __b(std::move(__init), *__first);
  30   return __init;
  31 }
  32
  33 template <class _InputIterator, class _Tp>
  34 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20 _Tp reduce(_InputIterator __first, _InputIterator __last,
  35                                                                    _Tp __init) {
  36   return _VSTD::reduce(__first, __last, __init, _VSTD::plus<>());
  37 }
  38
  39 template <class _InputIterator>
  40 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20 typename iterator_traits<_InputIterator>::value_type
  41 reduce(_InputIterator __first, _InputIterator __last) {
  42   return _VSTD::reduce(__first, __last, typename iterator_traits<_InputIterator>::value_type{});
  43 }
  44 #endif
  45
  46 _LIBCPP_END_NAMESPACE_STD
  47
  48 #endif // _LIBCPP___NUMERIC_REDUCE_H