[libcxx-commits] [libcxx] [libc++] Optimize ranges::for_each for iterating over __trees (PR #164405)

[Louis Dionne via libcxx-commits]

================
@@ -1409,6 +1431,21 @@ template <class _Key, class _Allocator, class = enable_if_t<__is_allocator_v<_Al
 multiset(initializer_list<_Key>, _Allocator) -> multiset<_Key, less<_Key>, _Allocator>;
 #  endif
 
+#  if _LIBCPP_STD_VER >= 14
+template <class _Alg, class _Key, class _Compare, class _Allocator>
+struct __specialized_algorithm<_Alg, multiset<_Key, _Compare, _Allocator>> {
+  using __set _LIBCPP_NODEBUG = multiset<_Key, _Compare, _Allocator>;
+
+  static const bool __has_algorithm = __specialized_algorithm<_Alg, typename __set::__base>::__has_algorithm;
+
+  // set's begin() and end() are identical with and without const qualifiaction
----------------
ldionne wrote:

```suggestion
  // set's begin() and end() are identical with and without const qualification
```

https://github.com/llvm/llvm-project/pull/164405