diff options
Diffstat (limited to 'libcxx/include/__iterator/iterator_traits.h')
| -rw-r--r-- | libcxx/include/__iterator/iterator_traits.h | 73 |
1 files changed, 44 insertions, 29 deletions
diff --git a/libcxx/include/__iterator/iterator_traits.h b/libcxx/include/__iterator/iterator_traits.h index c9d8944bfee3..248987e9b560 100644 --- a/libcxx/include/__iterator/iterator_traits.h +++ b/libcxx/include/__iterator/iterator_traits.h @@ -43,7 +43,7 @@ _LIBCPP_BEGIN_NAMESPACE_STD -#if _LIBCPP_STD_VER > 17 +#if _LIBCPP_STD_VER >= 20 template <class _Tp> using __with_reference = _Tp&; @@ -62,7 +62,7 @@ concept __dereferenceable = requires(_Tp& __t) { template<__dereferenceable _Tp> using iter_reference_t = decltype(*std::declval<_Tp&>()); -#endif // _LIBCPP_STD_VER > 17 +#endif // _LIBCPP_STD_VER >= 20 template <class _Iter> struct _LIBCPP_TEMPLATE_VIS iterator_traits; @@ -72,7 +72,7 @@ struct _LIBCPP_TEMPLATE_VIS output_iterator_tag {}; struct _LIBCPP_TEMPLATE_VIS forward_iterator_tag : public input_iterator_tag {}; struct _LIBCPP_TEMPLATE_VIS bidirectional_iterator_tag : public forward_iterator_tag {}; struct _LIBCPP_TEMPLATE_VIS random_access_iterator_tag : public bidirectional_iterator_tag {}; -#if _LIBCPP_STD_VER > 17 +#if _LIBCPP_STD_VER >= 20 struct _LIBCPP_TEMPLATE_VIS contiguous_iterator_tag : public random_access_iterator_tag {}; #endif @@ -157,7 +157,7 @@ public: static const bool value = decltype(__test<_Tp>(nullptr))::value; }; -#if _LIBCPP_STD_VER > 17 +#if _LIBCPP_STD_VER >= 20 // The `cpp17-*-iterator` exposition-only concepts have very similar names to the `Cpp17*Iterator` named requirements // from `[iterator.cpp17]`. To avoid confusion between the two, the exposition-only concepts have been banished to @@ -190,7 +190,7 @@ template<class _Ip> concept __cpp17_forward_iterator = __cpp17_input_iterator<_Ip> && constructible_from<_Ip> && - is_lvalue_reference_v<iter_reference_t<_Ip>> && + is_reference_v<iter_reference_t<_Ip>> && same_as<remove_cvref_t<iter_reference_t<_Ip>>, typename indirectly_readable_traits<_Ip>::value_type> && requires(_Ip __i) { @@ -381,7 +381,7 @@ struct iterator_traits : __iterator_traits<_Ip> { using __primary_template = iterator_traits; }; -#else // _LIBCPP_STD_VER > 17 +#else // _LIBCPP_STD_VER >= 20 template <class _Iter, bool> struct __iterator_traits {}; @@ -418,10 +418,10 @@ struct _LIBCPP_TEMPLATE_VIS iterator_traits using __primary_template = iterator_traits; }; -#endif // _LIBCPP_STD_VER > 17 +#endif // _LIBCPP_STD_VER >= 20 template<class _Tp> -#if _LIBCPP_STD_VER > 17 +#if _LIBCPP_STD_VER >= 20 requires is_object_v<_Tp> #endif struct _LIBCPP_TEMPLATE_VIS iterator_traits<_Tp*> @@ -431,7 +431,7 @@ struct _LIBCPP_TEMPLATE_VIS iterator_traits<_Tp*> typedef _Tp* pointer; typedef _Tp& reference; typedef random_access_iterator_tag iterator_category; -#if _LIBCPP_STD_VER > 17 +#if _LIBCPP_STD_VER >= 20 typedef contiguous_iterator_tag iterator_concept; #endif }; @@ -453,60 +453,60 @@ template <class _Tp, class _Up> struct __has_iterator_concept_convertible_to<_Tp, _Up, false> : false_type {}; template <class _Tp> -struct __is_cpp17_input_iterator : public __has_iterator_category_convertible_to<_Tp, input_iterator_tag> {}; +using __has_input_iterator_category = __has_iterator_category_convertible_to<_Tp, input_iterator_tag>; template <class _Tp> -struct __is_cpp17_forward_iterator : public __has_iterator_category_convertible_to<_Tp, forward_iterator_tag> {}; +using __has_forward_iterator_category = __has_iterator_category_convertible_to<_Tp, forward_iterator_tag>; template <class _Tp> -struct __is_cpp17_bidirectional_iterator : public __has_iterator_category_convertible_to<_Tp, bidirectional_iterator_tag> {}; +using __has_bidirectional_iterator_category = __has_iterator_category_convertible_to<_Tp, bidirectional_iterator_tag>; template <class _Tp> -struct __is_cpp17_random_access_iterator : public __has_iterator_category_convertible_to<_Tp, random_access_iterator_tag> {}; +using __has_random_access_iterator_category = __has_iterator_category_convertible_to<_Tp, random_access_iterator_tag>; -// __is_cpp17_contiguous_iterator determines if an iterator is known by +// __libcpp_is_contiguous_iterator determines if an iterator is known by // libc++ to be contiguous, either because it advertises itself as such // (in C++20) or because it is a pointer type or a known trivial wrapper // around a (possibly fancy) pointer type, such as __wrap_iter<T*>. // Such iterators receive special "contiguous" optimizations in // std::copy and std::sort. // -#if _LIBCPP_STD_VER > 17 +#if _LIBCPP_STD_VER >= 20 template <class _Tp> -struct __is_cpp17_contiguous_iterator : _Or< +struct __libcpp_is_contiguous_iterator : _Or< __has_iterator_category_convertible_to<_Tp, contiguous_iterator_tag>, __has_iterator_concept_convertible_to<_Tp, contiguous_iterator_tag> > {}; #else template <class _Tp> -struct __is_cpp17_contiguous_iterator : false_type {}; +struct __libcpp_is_contiguous_iterator : false_type {}; #endif // Any native pointer which is an iterator is also a contiguous iterator. template <class _Up> -struct __is_cpp17_contiguous_iterator<_Up*> : true_type {}; +struct __libcpp_is_contiguous_iterator<_Up*> : true_type {}; template <class _Iter> class __wrap_iter; template <class _Tp> -struct __is_exactly_cpp17_input_iterator - : public integral_constant<bool, +using __has_exactly_input_iterator_category + = integral_constant<bool, __has_iterator_category_convertible_to<_Tp, input_iterator_tag>::value && - !__has_iterator_category_convertible_to<_Tp, forward_iterator_tag>::value> {}; + !__has_iterator_category_convertible_to<_Tp, forward_iterator_tag>::value>; template <class _Tp> -struct __is_exactly_cpp17_forward_iterator - : public integral_constant<bool, +using __has_exactly_forward_iterator_category + = integral_constant<bool, __has_iterator_category_convertible_to<_Tp, forward_iterator_tag>::value && - !__has_iterator_category_convertible_to<_Tp, bidirectional_iterator_tag>::value> {}; + !__has_iterator_category_convertible_to<_Tp, bidirectional_iterator_tag>::value>; template <class _Tp> -struct __is_exactly_cpp17_bidirectional_iterator - : public integral_constant<bool, +using __has_exactly_bidirectional_iterator_category + = integral_constant<bool, __has_iterator_category_convertible_to<_Tp, bidirectional_iterator_tag>::value && - !__has_iterator_category_convertible_to<_Tp, random_access_iterator_tag>::value> {}; + !__has_iterator_category_convertible_to<_Tp, random_access_iterator_tag>::value>; template<class _InputIterator> using __iter_value_type = typename iterator_traits<_InputIterator>::value_type; @@ -531,8 +531,23 @@ using __iterator_pointer_type = typename iterator_traits<_Iter>::pointer; template <class _Iter> using __iter_diff_t = typename iterator_traits<_Iter>::difference_type; -template<class _InputIterator> -using __iter_value_type = typename iterator_traits<_InputIterator>::value_type; +template <class _Iter> +using __iter_reference = typename iterator_traits<_Iter>::reference; + +#if _LIBCPP_STD_VER >= 20 + +// [readable.traits] + +// Let `RI` be `remove_cvref_t<I>`. The type `iter_value_t<I>` denotes +// `indirectly_readable_traits<RI>::value_type` if `iterator_traits<RI>` names a specialization +// generated from the primary template, and `iterator_traits<RI>::value_type` otherwise. +// This has to be in this file and not readable_traits.h to break the include cycle between the two. +template <class _Ip> +using iter_value_t = typename conditional_t<__is_primary_template<iterator_traits<remove_cvref_t<_Ip> > >::value, + indirectly_readable_traits<remove_cvref_t<_Ip> >, + iterator_traits<remove_cvref_t<_Ip> > >::value_type; + +#endif // _LIBCPP_STD_VER >= 20 _LIBCPP_END_NAMESPACE_STD |