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

[Louis Dionne via libcxx-commits]

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@@ -1992,6 +2014,23 @@ multimap(initializer_list<pair<_Key, _Tp>>, _Allocator)
     -> multimap<remove_const_t<_Key>, _Tp, less<remove_const_t<_Key>>, _Allocator>;
 #  endif
 
+#  if _LIBCPP_STD_VER >= 14
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+struct __specialized_algorithm<_Algorithm::__for_each, multimap<_Key, _Tp, _Compare, _Allocator>> {
+  using __map _LIBCPP_NODEBUG = multimap<_Key, _Tp, _Compare, _Allocator>;
+
+  static const bool __has_algorithm = true;
+
+  // set's begin() and end() are identical with and without const qualifiaction
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ldionne wrote:

```suggestion
```

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