[libcxx-commits] [libcxx] [libc++] Optimize std::find for segmented iterators (PR #67224)

[via libcxx-commits]

================
@@ -118,8 +119,35 @@ __find_impl(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst>
   return std::__find_bool<false>(__first, static_cast<typename _Cp::size_type>(__last - __first));
 }
 
+// segmented iterator implementation
+
+template <class>
+struct __find_segment;
+
+template <class _SegmentedIterator,
+          class _Tp,
+          class _Proj,
+          __enable_if_t<__is_segmented_iterator<_SegmentedIterator>::value, int> = 0>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _SegmentedIterator
+__find_impl(_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);
+}
+
+template <class _Tp>
+struct __find_segment {
+  const _Tp& __value_;
+
+  __find_segment(const _Tp& __value) : __value_(__value) {}
+
+  template <class _InputIterator, class _Proj>
+  _InputIterator operator()(_InputIterator __first, _InputIterator __last, _Proj& __proj) {
+    return std::__find_impl(__first, __last, __value_, __proj);
+  }
+};
+
+// public API
 template <class _InputIterator, class _Tp>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20 _InputIterator
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _InputIterator
----------------
philnik777 wrote:

Nothing in particular. We can do it in this patch as well. I just thought a smaller more focused patch would be simpler.

https://github.com/llvm/llvm-project/pull/67224