Christopher Di Bella d10dc5a06f
[libc++] Remove dedicated namespaces for ranges functions (#76543)
We originally put implementation-detail function objects into individual
namespaces for `std::ranges` without a good reason for doing so. This
practice was continued, presumably because there was prior art. Since
there's no reason to keep these namespaces, this commit removes them,
which will slightly impact binary size.

This commit does not apply to CPOs, some of which need additional work.
2024-08-01 08:54:06 -04:00

80 lines
2.5 KiB
C++

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP___ITERATOR_NEXT_H
#define _LIBCPP___ITERATOR_NEXT_H
#include <__assert>
#include <__config>
#include <__iterator/advance.h>
#include <__iterator/concepts.h>
#include <__iterator/incrementable_traits.h>
#include <__iterator/iterator_traits.h>
#include <__type_traits/enable_if.h>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
template <class _InputIter, __enable_if_t<__has_input_iterator_category<_InputIter>::value, int> = 0>
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 _InputIter
next(_InputIter __x, typename iterator_traits<_InputIter>::difference_type __n = 1) {
// Calling `advance` with a negative value on a non-bidirectional iterator is a no-op in the current implementation.
// Note that this check duplicates the similar check in `std::advance`.
_LIBCPP_ASSERT_PEDANTIC(__n >= 0 || __has_bidirectional_iterator_category<_InputIter>::value,
"Attempt to next(it, n) with negative n on a non-bidirectional iterator");
std::advance(__x, __n);
return __x;
}
#if _LIBCPP_STD_VER >= 20
// [range.iter.op.next]
namespace ranges {
struct __next {
template <input_or_output_iterator _Ip>
_LIBCPP_HIDE_FROM_ABI constexpr _Ip operator()(_Ip __x) const {
++__x;
return __x;
}
template <input_or_output_iterator _Ip>
_LIBCPP_HIDE_FROM_ABI constexpr _Ip operator()(_Ip __x, iter_difference_t<_Ip> __n) const {
ranges::advance(__x, __n);
return __x;
}
template <input_or_output_iterator _Ip, sentinel_for<_Ip> _Sp>
_LIBCPP_HIDE_FROM_ABI constexpr _Ip operator()(_Ip __x, _Sp __bound_sentinel) const {
ranges::advance(__x, __bound_sentinel);
return __x;
}
template <input_or_output_iterator _Ip, sentinel_for<_Ip> _Sp>
_LIBCPP_HIDE_FROM_ABI constexpr _Ip operator()(_Ip __x, iter_difference_t<_Ip> __n, _Sp __bound_sentinel) const {
ranges::advance(__x, __n, __bound_sentinel);
return __x;
}
};
inline namespace __cpo {
inline constexpr auto next = __next{};
} // namespace __cpo
} // namespace ranges
#endif // _LIBCPP_STD_VER >= 20
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___ITERATOR_NEXT_H