vendor/llvm-project/llvmorg-16-init-18548-gb0daacf58f41

1 files changed, 81 insertions, 65 deletions

diff --git a/libcxx/include/__algorithm/unique_copy.h b/libcxx/include/__algorithm/unique_copy.h
index f58517749f51..81fcd50f011d 100644
--- a/libcxx/include/__algorithm/unique_copy.h
+++ b/libcxx/include/__algorithm/unique_copy.h
@@ -10,8 +10,14 @@
 #define _LIBCPP___ALGORITHM_UNIQUE_COPY_H
 
 #include <__algorithm/comp.h>
+#include <__algorithm/iterator_operations.h>
 #include <__config>
 #include <__iterator/iterator_traits.h>
+#include <__type_traits/conditional.h>
+#include <__type_traits/is_base_of.h>
+#include <__type_traits/is_same.h>
+#include <__utility/move.h>
+#include <__utility/pair.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
@@ -19,88 +25,98 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-template <class _BinaryPredicate, class _InputIterator, class _OutputIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
-__unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryPredicate __pred,
-              input_iterator_tag, output_iterator_tag)
-{
-    if (__first != __last)
-    {
-        typename iterator_traits<_InputIterator>::value_type __t(*__first);
+namespace __unique_copy_tags {
+
+struct __reread_from_input_tag {};
+struct __reread_from_output_tag {};
+struct __read_from_tmp_value_tag {};
+
+} // namespace __unique_copy_tags
+
+template <class _AlgPolicy, class _BinaryPredicate, class _InputIterator, class _Sent, class _OutputIterator>
+_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _OutputIterator>
+__unique_copy(_InputIterator __first,
+              _Sent __last,
+              _OutputIterator __result,
+              _BinaryPredicate&& __pred,
+              __unique_copy_tags::__read_from_tmp_value_tag) {
+  if (__first != __last) {
+    typename _IterOps<_AlgPolicy>::template __value_type<_InputIterator> __t(*__first);
+    *__result = __t;
+    ++__result;
+    while (++__first != __last) {
+      if (!__pred(__t, *__first)) {
+        __t       = *__first;
         *__result = __t;
         ++__result;
-        while (++__first != __last)
-        {
-            if (!__pred(__t, *__first))
-            {
-                __t = *__first;
-                *__result = __t;
-                ++__result;
-            }
-        }
+      }
     }
-    return __result;
+  }
+  return pair<_InputIterator, _OutputIterator>(std::move(__first), std::move(__result));
 }
 
-template <class _BinaryPredicate, class _ForwardIterator, class _OutputIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
-__unique_copy(_ForwardIterator __first, _ForwardIterator __last, _OutputIterator __result, _BinaryPredicate __pred,
-              forward_iterator_tag, output_iterator_tag)
-{
-    if (__first != __last)
-    {
-        _ForwardIterator __i = __first;
-        *__result = *__i;
+template <class _AlgPolicy, class _BinaryPredicate, class _ForwardIterator, class _Sent, class _OutputIterator>
+_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI pair<_ForwardIterator, _OutputIterator>
+__unique_copy(_ForwardIterator __first,
+              _Sent __last,
+              _OutputIterator __result,
+              _BinaryPredicate&& __pred,
+              __unique_copy_tags::__reread_from_input_tag) {
+  if (__first != __last) {
+    _ForwardIterator __i = __first;
+    *__result            = *__i;
+    ++__result;
+    while (++__first != __last) {
+      if (!__pred(*__i, *__first)) {
+        *__result = *__first;
         ++__result;
-        while (++__first != __last)
-        {
-            if (!__pred(*__i, *__first))
-            {
-                *__result = *__first;
-                ++__result;
-                __i = __first;
-            }
-        }
+        __i = __first;
+      }
     }
-    return __result;
+  }
+  return pair<_ForwardIterator, _OutputIterator>(std::move(__first), std::move(__result));
 }
 
-template <class _BinaryPredicate, class _InputIterator, class _ForwardIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
-__unique_copy(_InputIterator __first, _InputIterator __last, _ForwardIterator __result, _BinaryPredicate __pred,
-              input_iterator_tag, forward_iterator_tag)
-{
-    if (__first != __last)
-    {
-        *__result = *__first;
-        while (++__first != __last)
-            if (!__pred(*__result, *__first))
-                *++__result = *__first;
-        ++__result;
-    }
-    return __result;
+template <class _AlgPolicy, class _BinaryPredicate, class _InputIterator, class _Sent, class _InputAndOutputIterator>
+_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _InputAndOutputIterator>
+__unique_copy(_InputIterator __first,
+              _Sent __last,
+              _InputAndOutputIterator __result,
+              _BinaryPredicate&& __pred,
+              __unique_copy_tags::__reread_from_output_tag) {
+  if (__first != __last) {
+    *__result = *__first;
+    while (++__first != __last)
+      if (!__pred(*__result, *__first))
+        *++__result = *__first;
+    ++__result;
+  }
+  return pair<_InputIterator, _InputAndOutputIterator>(std::move(__first), std::move(__result));
 }
 
 template <class _InputIterator, class _OutputIterator, class _BinaryPredicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryPredicate __pred)
-{
-    return _VSTD::__unique_copy<_BinaryPredicate&>(__first, __last, __result, __pred,
-                               typename iterator_traits<_InputIterator>::iterator_category(),
-                               typename iterator_traits<_OutputIterator>::iterator_category());
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
+unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryPredicate __pred) {
+  using __algo_tag = __conditional_t<
+      is_base_of<forward_iterator_tag, typename iterator_traits<_InputIterator>::iterator_category>::value,
+      __unique_copy_tags::__reread_from_input_tag,
+      __conditional_t<
+          is_base_of<forward_iterator_tag, typename iterator_traits<_OutputIterator>::iterator_category>::value &&
+              is_same< typename iterator_traits<_InputIterator>::value_type,
+                       typename iterator_traits<_OutputIterator>::value_type>::value,
+          __unique_copy_tags::__reread_from_output_tag,
+          __unique_copy_tags::__read_from_tmp_value_tag> >;
+  return std::__unique_copy<_ClassicAlgPolicy>(
+             std::move(__first), std::move(__last), std::move(__result), __pred, __algo_tag())
+      .second;
 }
 
 template <class _InputIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
-{
-    typedef typename iterator_traits<_InputIterator>::value_type __v;
-    return _VSTD::unique_copy(__first, __last, __result, __equal_to<__v>());
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
+unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result) {
+  return std::unique_copy(std::move(__first), std::move(__last), std::move(__result), __equal_to());
 }
 
-
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP___ALGORITHM_UNIQUE_COPY_H