[libc++][NFC] Make __is_segmented_iterator a variable template (llvm#149976)

philnik777 · Jaddyen · commit 9c12f54325ab · 2025-07-25T21:02:23.000Z
diff --git a/libcxx/include/__algorithm/copy.h b/libcxx/include/__algorithm/copy.h
@@ -182,7 +182,7 @@ struct __copy_impl {
     }
   };
 
-  template <class _InIter, class _OutIter, __enable_if_t<__is_segmented_iterator<_InIter>::value, int> = 0>
+  template <class _InIter, class _OutIter, __enable_if_t<__is_segmented_iterator_v<_InIter>, int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter>
   operator()(_InIter __first, _InIter __last, _OutIter __result) const {
     std::__for_each_segment(__first, __last, _CopySegment<_InIter, _OutIter>(__result));
@@ -192,7 +192,7 @@ struct __copy_impl {
   template <class _InIter,
             class _OutIter,
             __enable_if_t<__has_random_access_iterator_category<_InIter>::value &&
-                              !__is_segmented_iterator<_InIter>::value && __is_segmented_iterator<_OutIter>::value,
+                              !__is_segmented_iterator_v<_InIter> && __is_segmented_iterator_v<_OutIter>,
                           int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter>
   operator()(_InIter __first, _InIter __last, _OutIter __result) const {
diff --git a/libcxx/include/__algorithm/copy_backward.h b/libcxx/include/__algorithm/copy_backward.h
@@ -170,7 +170,7 @@ struct __copy_backward_impl {
     return std::make_pair(std::move(__original_last_iter), std::move(__result));
   }
 
-  template <class _InIter, class _OutIter, __enable_if_t<__is_segmented_iterator<_InIter>::value, int> = 0>
+  template <class _InIter, class _OutIter, __enable_if_t<__is_segmented_iterator_v<_InIter>, int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter>
   operator()(_InIter __first, _InIter __last, _OutIter __result) const {
     using _Traits = __segmented_iterator_traits<_InIter>;
@@ -200,7 +200,7 @@ struct __copy_backward_impl {
   template <class _InIter,
             class _OutIter,
             __enable_if_t<__has_random_access_iterator_category<_InIter>::value &&
-                              !__is_segmented_iterator<_InIter>::value && __is_segmented_iterator<_OutIter>::value,
+                              !__is_segmented_iterator_v<_InIter> && __is_segmented_iterator_v<_OutIter>,
                           int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter>
   operator()(_InIter __first, _InIter __last, _OutIter __result) const {
diff --git a/libcxx/include/__algorithm/find.h b/libcxx/include/__algorithm/find.h
@@ -149,7 +149,7 @@ struct __find_segment;
 template <class _SegmentedIterator,
           class _Tp,
           class _Proj,
-          __enable_if_t<__is_segmented_iterator<_SegmentedIterator>::value, int> = 0>
+          __enable_if_t<__is_segmented_iterator_v<_SegmentedIterator>, int> = 0>
 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _SegmentedIterator
 __find(_SegmentedIterator __first, _SegmentedIterator __last, const _Tp& __value, _Proj& __proj) {
   return std::__find_segment_if(std::move(__first), std::move(__last), __find_segment<_Tp>(__value), __proj);
diff --git a/libcxx/include/__algorithm/for_each.h b/libcxx/include/__algorithm/for_each.h
@@ -39,7 +39,7 @@ __for_each(_InputIterator __first, _Sent __last, _Func& __f, _Proj& __proj) {
 template <class _SegmentedIterator,
           class _Func,
           class _Proj,
-          __enable_if_t<__is_segmented_iterator<_SegmentedIterator>::value, int> = 0>
+          __enable_if_t<__is_segmented_iterator_v<_SegmentedIterator>, int> = 0>
 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _SegmentedIterator
 __for_each(_SegmentedIterator __first, _SegmentedIterator __last, _Func& __func, _Proj& __proj) {
   using __local_iterator_t = typename __segmented_iterator_traits<_SegmentedIterator>::__local_iterator;
diff --git a/libcxx/include/__algorithm/for_each_n.h b/libcxx/include/__algorithm/for_each_n.h
@@ -37,8 +37,8 @@ template <class _InputIterator,
           class _Func,
           class _Proj,
           __enable_if_t<!__has_random_access_iterator_category<_InputIterator>::value &&
-                            _Or< _Not<__is_segmented_iterator<_InputIterator> >,
-                                 _Not<__has_random_access_local_iterator<_InputIterator> > >::value,
+                            _Or<integral_constant<bool, !__is_segmented_iterator_v<_InputIterator> >,
+                                _Not<__has_random_access_local_iterator<_InputIterator> > >::value,
                         int> = 0>
 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _InputIterator
 __for_each_n(_InputIterator __first, _Size __orig_n, _Func& __f, _Proj& __proj) {
@@ -71,7 +71,7 @@ template <class _SegmentedIterator,
           class _Func,
           class _Proj,
           __enable_if_t<!__has_random_access_iterator_category<_SegmentedIterator>::value &&
-                            __is_segmented_iterator<_SegmentedIterator>::value &&
+                            __is_segmented_iterator_v<_SegmentedIterator> &&
                             __has_random_access_iterator_category<
                                 typename __segmented_iterator_traits<_SegmentedIterator>::__local_iterator>::value,
                         int> = 0>
diff --git a/libcxx/include/__algorithm/for_each_n_segment.h b/libcxx/include/__algorithm/for_each_n_segment.h
@@ -27,7 +27,7 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 template <class _SegmentedIterator, class _Size, class _Functor>
 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _SegmentedIterator
 __for_each_n_segment(_SegmentedIterator __first, _Size __orig_n, _Functor __func) {
-  static_assert(__is_segmented_iterator<_SegmentedIterator>::value &&
+  static_assert(__is_segmented_iterator_v<_SegmentedIterator> &&
                     __has_random_access_iterator_category<
                         typename __segmented_iterator_traits<_SegmentedIterator>::__local_iterator>::value,
                 "__for_each_n_segment only works with segmented iterators with random-access local iterators");
diff --git a/libcxx/include/__algorithm/move.h b/libcxx/include/__algorithm/move.h
@@ -65,7 +65,7 @@ struct __move_impl {
     }
   };
 
-  template <class _InIter, class _OutIter, __enable_if_t<__is_segmented_iterator<_InIter>::value, int> = 0>
+  template <class _InIter, class _OutIter, __enable_if_t<__is_segmented_iterator_v<_InIter>, int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter>
   operator()(_InIter __first, _InIter __last, _OutIter __result) const {
     std::__for_each_segment(__first, __last, _MoveSegment<_InIter, _OutIter>(__result));
@@ -75,7 +75,7 @@ struct __move_impl {
   template <class _InIter,
             class _OutIter,
             __enable_if_t<__has_random_access_iterator_category<_InIter>::value &&
-                              !__is_segmented_iterator<_InIter>::value && __is_segmented_iterator<_OutIter>::value,
+                              !__is_segmented_iterator_v<_InIter> && __is_segmented_iterator_v<_OutIter>,
                           int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter>
   operator()(_InIter __first, _InIter __last, _OutIter __result) const {
diff --git a/libcxx/include/__algorithm/move_backward.h b/libcxx/include/__algorithm/move_backward.h
@@ -51,7 +51,7 @@ struct __move_backward_impl {
     return std::make_pair(std::move(__original_last_iter), std::move(__result));
   }
 
-  template <class _InIter, class _OutIter, __enable_if_t<__is_segmented_iterator<_InIter>::value, int> = 0>
+  template <class _InIter, class _OutIter, __enable_if_t<__is_segmented_iterator_v<_InIter>, int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter>
   operator()(_InIter __first, _InIter __last, _OutIter __result) const {
     using _Traits = __segmented_iterator_traits<_InIter>;
@@ -81,7 +81,7 @@ struct __move_backward_impl {
   template <class _InIter,
             class _OutIter,
             __enable_if_t<__has_random_access_iterator_category<_InIter>::value &&
-                              !__is_segmented_iterator<_InIter>::value && __is_segmented_iterator<_OutIter>::value,
+                              !__is_segmented_iterator_v<_InIter> && __is_segmented_iterator_v<_OutIter>,
                           int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter>
   operator()(_InIter __first, _InIter __last, _OutIter __result) const {
diff --git a/libcxx/include/__iterator/segmented_iterator.h b/libcxx/include/__iterator/segmented_iterator.h
@@ -67,13 +67,13 @@ struct __segmented_iterator_traits;
 */
 
 template <class _Tp, size_t = 0>
-struct __has_specialization : false_type {};
+inline const bool __has_specialization_v = false;
 
 template <class _Tp>
-struct __has_specialization<_Tp, sizeof(_Tp) * 0> : true_type {};
+inline const bool __has_specialization_v<_Tp, sizeof(_Tp) * 0> = true;
 
 template <class _Iterator>
-using __is_segmented_iterator _LIBCPP_NODEBUG = __has_specialization<__segmented_iterator_traits<_Iterator> >;
+inline const bool __is_segmented_iterator_v = __has_specialization_v<__segmented_iterator_traits<_Iterator> >;
 
 template <class _SegmentedIterator>
 struct __has_random_access_local_iterator
diff --git a/libcxx/include/deque b/libcxx/include/deque
@@ -461,9 +461,8 @@ private:
       __deque_iterator<_ValueType, _Pointer, _Reference, _MapPointer, _DiffType, _BlockSize>;
 
 public:
-  using __is_segmented_iterator _LIBCPP_NODEBUG = true_type;
-  using __segment_iterator _LIBCPP_NODEBUG      = _MapPointer;
-  using __local_iterator _LIBCPP_NODEBUG        = _Pointer;
+  using __segment_iterator _LIBCPP_NODEBUG = _MapPointer;
+  using __local_iterator _LIBCPP_NODEBUG   = _Pointer;
 
   static _LIBCPP_HIDE_FROM_ABI __segment_iterator __segment(_Iterator __iter) { return __iter.__m_iter_; }
   static _LIBCPP_HIDE_FROM_ABI __local_iterator __local(_Iterator __iter) { return __iter.__ptr_; }
diff --git a/libcxx/test/libcxx/containers/sequences/deque/segmented_iterator.compile.pass.cpp b/libcxx/test/libcxx/containers/sequences/deque/segmented_iterator.compile.pass.cpp
@@ -6,7 +6,9 @@
 //
 //===----------------------------------------------------------------------===//
 
+// XFAIL: FROZEN-CXX03-HEADERS-FIXME
+
 #include <deque>
 
 using DequeIterator = typename std::deque<int>::iterator;
-static_assert(std::__is_segmented_iterator<DequeIterator>::value, "");
+static_assert(std::__is_segmented_iterator_v<DequeIterator>, "");
diff --git a/libcxx/test/libcxx/ranges/range.adaptors/range.join/segmented_iterator.compile.pass.cpp b/libcxx/test/libcxx/ranges/range.adaptors/range.join/segmented_iterator.compile.pass.cpp
@@ -14,4 +14,4 @@
 
 using JoinView = decltype(std::views::join(std::declval<std::vector<std::vector<int>>&>()));
 using JoinIter = std::ranges::iterator_t<JoinView>;
-static_assert(std::__is_segmented_iterator<JoinIter>::value);
+static_assert(std::__is_segmented_iterator_v<JoinIter>);
