[libcxx-commits] [libcxx] [libc++] Optimize std::lexicographical_compare_three_way (PR #230336)

[Nikolas Klauser via libcxx-commits]

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@@ -50,13 +60,28 @@ _LIBCPP_HIDE_FROM_ABI constexpr auto __lexicographical_compare_three_way_fast_pa
   _Len2 __len2      = __last2 - __first2;
   _Common __min_len = std::min<_Common>(__len1, __len2);
 
-  for (_Common __i = 0; __i < __min_len; ++__i) {
-    auto __c = __comp(*__first1, *__first2);
-    if (__c != 0) {
-      return __c;
+  using _Tp = remove_pointer_t<_InputIterator1>;
+  if constexpr (is_pointer_v<_InputIterator1> && is_same_v<_InputIterator1, _InputIterator2> &&
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philnik777 wrote:

This currently fails for comparing `T*` and `const T*`, which is quite unfortunate. Can we improve that?

https://github.com/llvm/llvm-project/pull/230336