[libcxx-commits] [libcxx] 5e23f8a - [libc++] Fix __gnu_cxx::hash_multimap copy construction (#160043)

[via libcxx-commits]

Author: Nikolas Klauser
Date: 2025-09-23T16:15:20+02:00
New Revision: 5e23f8aa83a82e8ef81f013efc71484475bcfd94

URL: https://github.com/llvm/llvm-project/commit/5e23f8aa83a82e8ef81f013efc71484475bcfd94
DIFF: https://github.com/llvm/llvm-project/commit/5e23f8aa83a82e8ef81f013efc71484475bcfd94.diff

LOG: [libc++] Fix __gnu_cxx::hash_multimap copy construction (#160043)

Added: 
    libcxx/test/extensions/gnu/hash_multimap/copy.pass.cpp

Modified: 
    libcxx/include/ext/hash_map

Removed: 
    


################################################################################
diff  --git a/libcxx/include/ext/hash_map b/libcxx/include/ext/hash_map
index 70c2fbeec2959..01ca7498f0cc1 100644
--- a/libcxx/include/ext/hash_map
+++ b/libcxx/include/ext/hash_map
@@ -787,10 +787,7 @@ hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_multimap(
 }
 
 template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_multimap(const hash_multimap& __u) : __table_(__u.__table_) {
-  __table_.__rehash_multi(__u.bucket_count());
-  insert(__u.begin(), __u.end());
-}
+hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_multimap(const hash_multimap& __u) : __table_(__u.__table_) {}
 
 template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
 template <class _InputIterator>

diff  --git a/libcxx/test/extensions/gnu/hash_multimap/copy.pass.cpp b/libcxx/test/extensions/gnu/hash_multimap/copy.pass.cpp
new file mode 100644
index 0000000000000..9f9737b28e44d
--- /dev/null
+++ b/libcxx/test/extensions/gnu/hash_multimap/copy.pass.cpp
@@ -0,0 +1,27 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// ADDITIONAL_COMPILE_FLAGS: -Wno-deprecated
+
+// hash_multimap::hash_multimap(const hash_multimap&)
+
+#include <cassert>
+#include <ext/hash_map>
+
+int main(int, char**) {
+  __gnu_cxx::hash_multimap<int, int> map;
+
+  map.insert(std::make_pair(1, 1));
+  map.insert(std::make_pair(1, 1));
+
+  auto map2 = map;
+
+  assert(map2.size() == 2);
+
+  return 0;
+}