llvm-capstone/libcxx/include/__iterator/incrementable_traits.h
Louis Dionne 9783f28cbb
[libc++] Format the code base (#74334)
This patch runs clang-format on all of libcxx/include and libcxx/src, in
accordance with the RFC discussed at [1]. Follow-up patches will format
the benchmarks, the test suite and remaining parts of the code. I'm
splitting this one into its own patch so the diff is a bit easier to
review.

This patch was generated with:

   find libcxx/include libcxx/src -type f \
      | grep -v 'module.modulemap.in' \
      | grep -v 'CMakeLists.txt' \
      | grep -v 'README.txt' \
      | grep -v 'libcxx.imp' \
      | grep -v '__config_site.in' \
      | xargs clang-format -i

A Git merge driver is available in libcxx/utils/clang-format-merge-driver.sh
to help resolve merge and rebase issues across these formatting changes.

[1]: https://discourse.llvm.org/t/rfc-clang-formatting-all-of-libc-once-and-for-all
2023-12-18 14:01:33 -05:00

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_INCREMENTABLE_TRAITS_H
#define _LIBCPP___ITERATOR_INCREMENTABLE_TRAITS_H
#include <__concepts/arithmetic.h>
#include <__config>
#include <__type_traits/conditional.h>
#include <__type_traits/is_object.h>
#include <__type_traits/is_primary_template.h>
#include <__type_traits/make_signed.h>
#include <__type_traits/remove_cvref.h>
#include <__utility/declval.h>
#include <cstddef>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
#if _LIBCPP_STD_VER >= 20
// [incrementable.traits]
template <class>
struct incrementable_traits {};
template <class _Tp>
requires is_object_v<_Tp>
struct incrementable_traits<_Tp*> {
using difference_type = ptrdiff_t;
};
template <class _Ip>
struct incrementable_traits<const _Ip> : incrementable_traits<_Ip> {};
template <class _Tp>
concept __has_member_difference_type = requires { typename _Tp::difference_type; };
template <__has_member_difference_type _Tp>
struct incrementable_traits<_Tp> {
using difference_type = typename _Tp::difference_type;
};
template <class _Tp>
concept __has_integral_minus = requires(const _Tp& __x, const _Tp& __y) {
{ __x - __y } -> integral;
};
template <__has_integral_minus _Tp>
requires(!__has_member_difference_type<_Tp>)
struct incrementable_traits<_Tp> {
using difference_type = make_signed_t<decltype(std::declval<_Tp>() - std::declval<_Tp>())>;
};
template <class>
struct iterator_traits;
// Let `RI` be `remove_cvref_t<I>`. The type `iter_difference_t<I>` denotes
// `incrementable_traits<RI>::difference_type` if `iterator_traits<RI>` names a specialization
// generated from the primary template, and `iterator_traits<RI>::difference_type` otherwise.
template <class _Ip>
using iter_difference_t =
typename conditional_t<__is_primary_template<iterator_traits<remove_cvref_t<_Ip> > >::value,
incrementable_traits<remove_cvref_t<_Ip> >,
iterator_traits<remove_cvref_t<_Ip> > >::difference_type;
#endif // _LIBCPP_STD_VER >= 20
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___ITERATOR_INCREMENTABLE_TRAITS_H