[skip ci] beautified some badges

* Add tests for member of pointer operator for bucket iterators

* Fix erroneous conversion from node* to value_type* in bucket iterators

Originally caughy by vslashg  from PR https://github.com/boostorg/unordered/pull/220

* Update change log

* Update GHA config to use containers in C++20 builds for clang-14 as it's incompatible with libstdc++-13

* fixed Python installation problem

* tried variation of former fix

* tried another variation of former fix

* tried yet another variation

* editorial

---------

Co-authored-by: Christian Mazakas <christian.mazakas@gmail.com>

.github/workflows/ci.yml

@@ -95,12 +95,12 @@ jobs:
           - { name: "clang-14 w/ sanitizers (17)", sanitize: yes,
               compiler: clang-14,  cxxstd: '17',    os: 'ubuntu-22.04', ccache_key: "san2" }
           - { name: "clang-14 w/ sanitizers (20)", sanitize: yes,
-              compiler: clang-14,  cxxstd: '20',    os: 'ubuntu-22.04', ccache_key: "san2" }
+              compiler: clang-14,  cxxstd: '20',   container: 'ubuntu:22.04',  os: 'ubuntu-latest', ccache_key: "san2" }
           - { name: "clang-14 w/ sanitizers (2b)", sanitize: yes,
-              compiler: clang-14,  cxxstd: '2b',    os: 'ubuntu-22.04', ccache_key: "san2" }
+              compiler: clang-14,  cxxstd: '2b',   container: 'ubuntu:22.04',  os: 'ubuntu-latest', ccache_key: "san2" }
 
           - { name: "cfoa tsan (clang-14)", cxxstd: '11,14,17,20,2b', os: 'ubuntu-22.04', compiler: clang-14,
-              targets: 'libs/unordered/test//cfoa_tests', thread-sanitize: yes, 
+              targets: 'libs/unordered/test//cfoa_tests', thread-sanitize: yes,
               stdlib: libc++, install: 'clang-14 libc++-14-dev libc++abi-14-dev', ccache_key: "tsan" }
 
           - { compiler: 'clang-15', cxxstd: '11,14',    os: 'ubuntu-22.04', stdlib: libc++, install: 'clang-15 libc++-15-dev libc++abi-15-dev' }
@@ -134,7 +134,7 @@ jobs:
                 apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys E1DD270288B4E6030699E45FA1715D88E1DF1F24
                 for i in {1..${NET_RETRY_COUNT:-3}}; do sudo -E add-apt-repository -y ppa:git-core/ppa && break || sleep 10; done
                 apt-get -o Acquire::Retries=$NET_RETRY_COUNT update
-                apt-get -o Acquire::Retries=$NET_RETRY_COUNT install -y g++ python libpython-dev git
+                apt-get -o Acquire::Retries=$NET_RETRY_COUNT install -y g++ python-is-python3 git
             fi
             # For jobs not compatible with ccache, use "ccache: no" in the matrix
             if [[ "${{ matrix.ccache }}" == "no" ]]; then

README.md

@@ -1,49 +1,73 @@
 # Boost.Unordered
 
-Part of collection of the [Boost C++ Libraries](http://github.com/boostorg).
+[![Branch](https://img.shields.io/badge/branch-master-brightgreen.svg)](https://github.com/boostorg/unordered/tree/master) [![CI](https://github.com/boostorg/unordered/actions/workflows/ci.yml/badge.svg?branch=master)](https://github.com/boostorg/unordered/actions/workflows/ci.yml) [![Drone status](https://img.shields.io/drone/build/boostorg/unordered/master?server=https%3A%2F%2Fdrone.cpp.al&logo=drone&logoColor=%23CCCCCC&label=CI)](https://drone.cpp.al/boostorg/unordered) [![Build status](https://img.shields.io/appveyor/build/cppalliance/unordered/master?logo=appveyor&label=CI)](https://ci.appveyor.com/project/cppalliance/unordered/branch/master)  [![codecov](https://codecov.io/gh/boostorg/unordered/branch/master/graph/badge.svg)](https://codecov.io/gh/boostorg/unordered/branch/master)  [![Deps](https://img.shields.io/badge/deps-master-brightgreen.svg)](https://pdimov.github.io/boostdep-report/master/unordered.html)  [![Documentation](https://img.shields.io/badge/docs-master-brightgreen.svg)](https://www.boost.org/doc/libs/master/libs/unordered/doc/html/unordered.html)  [![Enter the Matrix](https://img.shields.io/badge/matrix-master-brightgreen.svg)](http://www.boost.org/development/tests/master/developer/unordered.html)<br/>
+[![Branch](https://img.shields.io/badge/branch-develop-brightgreen.svg)](https://github.com/boostorg/unordered/tree/develop) [![CI](https://github.com/boostorg/unordered/actions/workflows/ci.yml/badge.svg?branch=develop)](https://github.com/boostorg/unordered/actions/workflows/ci.yml) [![Drone status](https://img.shields.io/drone/build/boostorg/unordered/develop?server=https%3A%2F%2Fdrone.cpp.al&logo=drone&logoColor=%23CCCCCC&label=CI)](https://drone.cpp.al/boostorg/unordered) [![Build status](https://img.shields.io/appveyor/build/cppalliance/unordered/master?logo=appveyor&label=CI)](https://ci.appveyor.com/project/cppalliance/unordered/branch/develop) [![codecov](https://codecov.io/gh/boostorg/unordered/branch/develop/graph/badge.svg)](https://codecov.io/gh/boostorg/unordered/branch/develop) [![Deps](https://img.shields.io/badge/deps-develop-brightgreen.svg)](https://pdimov.github.io/boostdep-report/develop/unordered.html) [![Documentation](https://img.shields.io/badge/docs-develop-brightgreen.svg)](https://www.boost.org/doc/libs/develop/libs/unordered/doc/html/unordered.html) [![Enter the Matrix](https://img.shields.io/badge/matrix-develop-brightgreen.svg)](http://www.boost.org/development/tests/develop/developer/unordered.html)<br/>
+[![BSL 1.0](https://img.shields.io/badge/license-BSL_1.0-blue.svg)](https://www.boost.org/users/license.html) <img alt="C++11 required" src="https://img.shields.io/badge/standard-C%2b%2b11-blue.svg"> <img alt="Header-only library" src="https://img.shields.io/badge/build-header--only-blue.svg">
 
-For accessing data based on key lookup, the C++ standard library offers `std::set`, `std::map`, `std::multiset` and `std::multimap`.
-These are generally implemented using balanced binary trees so that lookup time has logarithmic complexity.
-That is generally okay, but in many cases a hash table can perform better, as accessing data has constant complexity, on average.
-The worst case complexity is linear, but that occurs rarely and with some care, can be avoided.
+Boost.Unordered offers a catalog of hash containers with different standards compliance levels, performances and intented usage scenarios:
 
-Also, the existing containers require a 'less than' comparison object to order their elements.
-For some data types this is impossible to implement or isn’t practical.
-In contrast, a hash table only needs an equality function and a hash function for the key.
+**`boost::unordered_set` `boost::unordered_map` `boost::unordered_multiset` `boost::unordered_multimap`**
 
-With this in mind, unordered associative containers were added to the C++ standard.
-This is an implementation of the containers described in C++11, with some deviations from the standard in order to work with non-C++11 compilers and libraries.
+<ul>Fully conformant implementations of <code>std::unordered_[multi](set|map)</code>,
+but faster and up to the latest revisions of the standard even if you're working in an older version of C++ (heterogeneous lookup,
+<code>try_emplace</code>, <code>contains</code>, etc.)</ul>
 
+**`boost::unordered_flat_set` `boost::unordered_flat_map`**
 
-### License
+<ul>The fastest of the lot. Based on open addressing, these containers slightly
+deviate from the standard in exchange for top performance.</ul>
 
-Distributed under the [Boost Software License, Version 1.0](http://www.boost.org/LICENSE_1_0.txt).
+**`boost::unordered_node_set` `boost::unordered_node_map`**
 
-### Properties
+<ul>Variations of <code>boost::unordered_flat_(set|map)</code> providing pointer stability.</ul>
 
-* C++03
-* Header-Only
+**`boost::concurrent_flat_set` `boost::concurrent_flat_map`**
 
-### Build Status
+<ul>High performance for multithreaded scenarios. Introducing a new non-standard, iterator-free API.</ul>
 
-Branch          | GH Actions | Appveyor | codecov.io | Deps | Docs | Tests |
-:-------------: | ---------- | -------- | ---------- | ---- | ---- | ----- |
-[`master`](https://github.com/boostorg/unordered/tree/master)   | [![CI](https://github.com/boostorg/unordered/actions/workflows/ci.yml/badge.svg?branch=master)](https://github.com/boostorg/unordered/actions/workflows/ci.yml)  | [![Build status](https://ci.appveyor.com/api/projects/status/github/boostorg/unordered?branch=master&svg=true)](https://ci.appveyor.com/project/danieljames/unordered-qtwe6/branch/master)   | [![codecov](https://codecov.io/gh/boostorg/unordered/branch/master/graph/badge.svg)](https://codecov.io/gh/boostorg/unordered/branch/master)   | [![Deps](https://img.shields.io/badge/deps-master-brightgreen.svg)](https://pdimov.github.io/boostdep-report/master/unordered.html)   | [![Documentation](https://img.shields.io/badge/docs-master-brightgreen.svg)](https://www.boost.org/doc/libs/master/libs/unordered/doc/html/unordered.html)   | [![Enter the Matrix](https://img.shields.io/badge/matrix-master-brightgreen.svg)](http://www.boost.org/development/tests/master/developer/unordered.html)
-[`develop`](https://github.com/boostorg/unordered/tree/develop) | [![CI](https://github.com/boostorg/unordered/actions/workflows/ci.yml/badge.svg?branch=develop)](https://github.com/boostorg/unordered/actions/workflows/ci.yml) | [![Build status](https://ci.appveyor.com/api/projects/status/github/boostorg/unordered?branch=develop&svg=true)](https://ci.appveyor.com/project/danieljames/unordered-qtwe6/branch/develop) | [![codecov](https://codecov.io/gh/boostorg/unordered/branch/develop/graph/badge.svg)](https://codecov.io/gh/boostorg/unordered/branch/develop) | [![Deps](https://img.shields.io/badge/deps-develop-brightgreen.svg)](https://pdimov.github.io/boostdep-report/develop/unordered.html) | [![Documentation](https://img.shields.io/badge/docs-develop-brightgreen.svg)](https://www.boost.org/doc/libs/develop/libs/unordered/doc/html/unordered.html) | [![Enter the Matrix](https://img.shields.io/badge/matrix-develop-brightgreen.svg)](http://www.boost.org/development/tests/develop/developer/unordered.html)
+## Learn about Boost.Unordered
 
-### Directories
+* [Online documentation](https://boost.org/libs/unordered)
+* [Some benchmarks](https://github.com/boostorg/boost_unordered_benchmarks)
+* Technical articles on Boost.Unordered internal design:
+  * [Advancing the state of the art for `std::unordered_map` implementations](https://bannalia.blogspot.com/2022/06/advancing-state-of-art-for.html)
+  * [Inside `boost::unordered_flat_map`](https://bannalia.blogspot.com/2022/11/inside-boostunorderedflatmap.html)
+  * [Inside `boost::concurrent_flat_map`](https://bannalia.blogspot.com/2023/07/inside-boostconcurrentflatmap.html)
+  * [Bulk visitation in `boost::concurrent_flat_map`](https://bannalia.blogspot.com/2023/10/bulk-visitation-in-boostconcurrentflatm.html)
 
-| Name        | Purpose                        |
-| ----------- | ------------------------------ |
-| `doc`       | documentation                  |
-| `example`   | examples                       |
-| `include`   | headers                        |
-| `test`      | unit tests                     |
+## Get the library
 
-### More information
+Boost.Unordered can be installed in a number of ways:
 
-* [Ask questions](http://stackoverflow.com/questions/ask?tags=c%2B%2B,boost,boost-unordered)
-* [Report bugs](https://github.com/boostorg/unordered/issues): Be sure to mention Boost version, platform and compiler you're using. A small compilable code sample to reproduce the problem is always good as well.
-* Submit your patches as pull requests against **develop** branch. Note that by submitting patches you agree to license your modifications under the [Boost Software License, Version 1.0](http://www.boost.org/LICENSE_1_0.txt).
-* Discussions about the library are held on the [Boost developers mailing list](http://www.boost.org/community/groups.html#main). Be sure to read the [discussion policy](http://www.boost.org/community/policy.html) before posting and add the `[unordered]` tag at the beginning of the subject line.
+* [Download Boost](https://www.boost.org/users/download/) and you're ready to go (this is a header-only library requiring no building).
+* Using Conan 2: In case you don't have it yet, add an entry for Boost in your `conanfile.txt` (the example requires at least Boost 1.83):
+```
+[requires]
+boost/[>=1.83.0]
+```
+<ul>If you're not using any compiled Boost library, the following will skip building altogether:</ul>
 
+```
+[options]
+boost:header_only=True
+```
+* Using vcpkg: Execute the command
+```
+vcpkg install boost-unordered
+```
+* Using CMake: [Boost CMake support infrastructure](https://github.com/boostorg/cmake)
+allows you to use CMake directly to download, build and consume all of Boost or
+some specific libraries.
+
+## Support
+
+* Join the **#boost-unordered** discussion group at [cpplang.slack.com](https://cpplang.slack.com/)
+([ask for an invite](https://cppalliance.org/slack/) if you’re not a member of this workspace yet)
+* Ask in the [Boost Users mailing list](https://lists.boost.org/mailman/listinfo.cgi/boost-users)
+(add the `[unordered]` tag at the beginning of the subject line)
+* [File an issue](https://github.com/boostorg/unordered/issues)
+
+## Contribute
+
+* [Pull requests](https://github.com/boostorg/unordered/pulls) against **develop** branch are most welcome.
+Note that by submitting patches you agree to license your modifications under the [Boost Software License, Version 1.0](http://www.boost.org/LICENSE_1_0.txt).

doc/unordered/benchmarks.adoc

@@ -10,7 +10,7 @@ All benchmarks were created using `unordered_set<unsigned int>` (non-duplicate)
 
 The insertion benchmarks insert `n` random values, where `n` is between 10,000 and 3 million. For the duplicated benchmarks, the same random values are repeated an average of 5 times.
 
-The erasure benchmarks erase all `n` elements randomly until the container is empty.
+The erasure benchmarks erase all `n` elements randomly until the container is empty. Erasure by key uses `erase(const key_type&)` to remove entire groups of equivalent elements in each operation.
 
 The successful lookup benchmarks are done by looking up all `n` values, in their original insertion order.
 
@@ -30,7 +30,7 @@ The unsuccessful lookup benchmarks use `n` randomly generated integers but using
 
 h|non-duplicate elements 
 h|duplicate elements 
-h|duplicate elements +
+h|duplicate elements, +
 max load factor 5
 |===
 
@@ -64,8 +64,18 @@ prior `reserve`
 
 h|non-duplicate elements 
 h|duplicate elements 
-h|duplicate elements +
+h|duplicate elements, +
 max load factor 5
+
+|
+|image::benchmarks-set/gcc/scattered%20erasure%20by%20key.xlsx.practice non-unique.png[width=250,link=../diagrams/benchmarks-set/gcc/scattered%20erasure%20by%20key.xlsx.practice non-unique.png,window=_blank]
+|image::benchmarks-set/gcc/scattered%20erasure%20by%20key.xlsx.practice non-unique 5.png[width=250,link=../diagrams/benchmarks-set/gcc/scattered%20erasure%20by%20key.xlsx.practice non-unique 5.png,window=_blank]
+
+|
+h|by key, duplicate elements 
+h|by key, duplicate elements, +
+max load factor 5
+
 |===
 
 ==== Successful Lookup
@@ -154,6 +164,15 @@ h|duplicate elements
 h|duplicate elements, +
 max load factor 5
 
+|
+|image::benchmarks-set/clang_libcpp/scattered%20erasure%20by%20key.xlsx.practice non-unique.png[width=250,link=../diagrams/benchmarks-set/clang_libcpp/scattered%20erasure%20by%20key.xlsx.practice non-unique.png,window=_blank]
+|image::benchmarks-set/clang_libcpp/scattered%20erasure%20by%20key.xlsx.practice non-unique 5.png[width=250,link=../diagrams/benchmarks-set/clang_libcpp/scattered%20erasure%20by%20key.xlsx.practice non-unique 5.png,window=_blank]
+
+|
+h|by key, duplicate elements 
+h|by key, duplicate elements, +
+max load factor 5
+
 |===
 
 ==== Successful lookup
@@ -242,6 +261,15 @@ h|duplicate elements
 h|duplicate elements, +
 max load factor 5
 
+|
+|image::benchmarks-set/vs/scattered%20erasure%20by%20key.xlsx.practice non-unique.png[width=250,link=../diagrams/benchmarks-set/vs/scattered%20erasure%20by%20key.xlsx.practice non-unique.png,window=_blank]
+|image::benchmarks-set/vs/scattered%20erasure%20by%20key.xlsx.practice non-unique 5.png[width=250,link=../diagrams/benchmarks-set/vs/scattered%20erasure%20by%20key.xlsx.practice non-unique 5.png,window=_blank]
+
+|
+h|by key, duplicate elements 
+h|by key, duplicate elements, +
+max load factor 5
+
 |===
 
 ==== Successful lookup

doc/unordered/changes.adoc

@@ -19,6 +19,9 @@ a concurrent container from user code.
 * Added Boost.Serialization support to all containers and their (non-local) iterator types.
 * Added support for fancy pointers to open-addressing and concurrent containers.
   This enables scenarios like the use of Boost.Interprocess allocators to construct containers in shared memory.
+* Fixed bug in member of pointer operator for local iterators of closed-addressing
+  containers ({github-pr-url}/221[PR#221^], credit goes to GitHub user vslashg for finding
+  and fixing this issue).
 * Starting with this release, `boost::unordered_[multi]set` and `boost::unordered_[multi]map`
   only work with C++11 onwards.
 
@@ -39,7 +42,7 @@ when the returned proxy is not used.
   `boost::unordered_node_map` and `boost::unordered_node_set`.
 * Extended heterogeneous lookup to more member functions as specified in
   https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2023/p2363r5.html[P2363].
-* Replaced the previous post-mixing process for open-addressing containers with 
+* Replaced the previous post-mixing process for open-addressing containers with
   a new algorithm based on extended multiplication by a constant.
 * Fixed bug in internal emplace() impl where stack-local types were not properly
   constructed using the Allocator of the container which breaks uses-allocator
@@ -56,20 +59,20 @@ when the returned proxy is not used.
 
 * Refactor internal implementation to be dramatically faster
 * Allow `final` Hasher and KeyEqual objects
-* Update documentation, adding benchmark graphs and notes on the new internal 
+* Update documentation, adding benchmark graphs and notes on the new internal
   data structures
 
 == Release 1.79.0
 
 * Improved {cpp}20 support:
-  ** All containers have been updated to support 
+  ** All containers have been updated to support
     heterogeneous `count`, `equal_range` and `find`.
   ** All containers now implement the member function `contains`.
   ** `erase_if` has been implemented for all containers.
 * Improved {cpp}23 support:
   ** All containers have been updated to support
     heterogeneous `erase` and `extract`.
-* Changed behavior of `reserve` to eagerly 
+* Changed behavior of `reserve` to eagerly
   allocate ({github-pr-url}/59[PR#59^]).
 * Various warning fixes in the test suite.
 * Update code to internally use `boost::allocator_traits`.

doc/unordered/unordered_node_map.adoc

@@ -1216,6 +1216,12 @@ template<class H2, class P2>
 
 Transfers all the element nodes from `source` whose key is not already present in `*this`.
 
+[horizontal]
+Requires:;; `this\->get_allocator() == source.get_allocator()`.
+Notes:;; Invalidates iterators to the elements transferred.
+If the resulting size of `*this` is greater than its original maximum load,
+invalidates all iterators associated to `*this`.
+
 ---
 
 === Observers

doc/unordered/unordered_node_set.adoc

@@ -1030,6 +1030,12 @@ template<class H2, class P2>
 
 Transfers all the element nodes from `source` whose key is not already present in `*this`.
 
+[horizontal]
+Requires:;; `this\->get_allocator() == source.get_allocator()`.
+Notes:;; Invalidates iterators to the elements transferred.
+If the resulting size of `*this` is greater than its original maximum load,
+invalidates all iterators associated to `*this`.
+
 ---
 
 === Observers

include/boost/unordered/concurrent_flat_map.hpp

@@ -855,8 +855,6 @@ namespace boost {
 #endif
 
   } // namespace unordered
-
-  using unordered::concurrent_flat_map;
 } // namespace boost
 
 #endif // BOOST_UNORDERED_CONCURRENT_FLAT_MAP_HPP

include/boost/unordered/concurrent_flat_map_fwd.hpp

@@ -46,9 +46,6 @@ namespace boost {
   } // namespace unordered
 
   using boost::unordered::concurrent_flat_map;
-  using boost::unordered::swap;
-  using boost::unordered::operator==;
-  using boost::unordered::operator!=;
 } // namespace boost
 
 #endif // BOOST_UNORDERED_CONCURRENT_FLAT_MAP_HPP

include/boost/unordered/concurrent_flat_set.hpp

@@ -711,8 +711,6 @@ namespace boost {
 #endif
 
   } // namespace unordered
-
-  using unordered::concurrent_flat_set;
 } // namespace boost
 
 #endif // BOOST_UNORDERED_CONCURRENT_FLAT_SET_HPP

include/boost/unordered/concurrent_flat_set_fwd.hpp

@@ -47,9 +47,6 @@ namespace boost {
   } // namespace unordered
 
   using boost::unordered::concurrent_flat_set;
-  using boost::unordered::swap;
-  using boost::unordered::operator==;
-  using boost::unordered::operator!=;
 } // namespace boost
 
 #endif // BOOST_UNORDERED_CONCURRENT_FLAT_SET_FWD_HPP

include/boost/unordered/detail/fca.hpp

@@ -318,7 +318,10 @@ namespace boost {
 
         reference operator*() const noexcept { return dereference(); }
 
-        pointer operator->() const noexcept { return boost::to_address(p); }
+        pointer operator->() const noexcept
+        {
+          return std::addressof(dereference());
+        }
 
         grouped_local_bucket_iterator& operator++() noexcept
         {
@@ -386,7 +389,10 @@ namespace boost {
 
         reference operator*() const noexcept { return dereference(); }
 
-        pointer operator->() const noexcept { return boost::to_address(p); }
+        pointer operator->() const noexcept
+        {
+          return std::addressof(dereference());
+        }
 
         const_grouped_local_bucket_iterator& operator++() noexcept
         {

include/boost/unordered/detail/foa/concurrent_table.hpp

@@ -1216,7 +1216,8 @@ private:
       auto mask=masks[i]=(this->arrays.groups()+pos)->match(hash);
       if(mask){
         BOOST_UNORDERED_PREFETCH(this->arrays.group_accesses()+pos);
-        BOOST_UNORDERED_PREFETCH_ELEMENTS(this->arrays.elements()+pos*N,N);
+        BOOST_UNORDERED_PREFETCH(
+          this->arrays.elements()+pos*N+unchecked_countr_zero(mask));
       }
     }
 

include/boost/unordered/unordered_flat_map_fwd.hpp

@@ -39,10 +39,6 @@ namespace boost {
   } // namespace unordered
 
   using boost::unordered::unordered_flat_map;
-
-  using boost::unordered::swap;
-  using boost::unordered::operator==;
-  using boost::unordered::operator!=;
 } // namespace boost
 
 #endif

include/boost/unordered/unordered_flat_set_fwd.hpp

@@ -39,10 +39,6 @@ namespace boost {
   } // namespace unordered
 
   using boost::unordered::unordered_flat_set;
-
-  using boost::unordered::swap;
-  using boost::unordered::operator==;
-  using boost::unordered::operator!=;
 } // namespace boost
 
 #endif

include/boost/unordered/unordered_map_fwd.hpp

@@ -60,11 +60,8 @@ namespace boost {
     template <class Iter, class NodeType> struct insert_return_type_map;
   } // namespace unordered
 
-  using boost::unordered::swap;
   using boost::unordered::unordered_map;
   using boost::unordered::unordered_multimap;
-  using boost::unordered::operator==;
-  using boost::unordered::operator!=;
 } // namespace boost
 
 #endif

include/boost/unordered/unordered_node_map.hpp

@@ -529,6 +529,7 @@ namespace boost {
         unordered_node_map<key_type, mapped_type, H2, P2, allocator_type>&
           source)
       {
+        BOOST_ASSERT(get_allocator() == source.get_allocator());
         table_.merge(source.table_);
       }
 
@@ -537,6 +538,7 @@ namespace boost {
         unordered_node_map<key_type, mapped_type, H2, P2, allocator_type>&&
           source)
       {
+        BOOST_ASSERT(get_allocator() == source.get_allocator());
         table_.merge(std::move(source.table_));
       }
 

include/boost/unordered/unordered_node_map_fwd.hpp

@@ -39,10 +39,6 @@ namespace boost {
   } // namespace unordered
 
   using boost::unordered::unordered_node_map;
-
-  using boost::unordered::swap;
-  using boost::unordered::operator==;
-  using boost::unordered::operator!=;
 } // namespace boost
 
 #endif

include/boost/unordered/unordered_node_set.hpp

@@ -415,12 +415,14 @@ namespace boost {
       template <class H2, class P2>
       void merge(unordered_node_set<key_type, H2, P2, allocator_type>& source)
       {
+        BOOST_ASSERT(get_allocator() == source.get_allocator());
         table_.merge(source.table_);
       }
 
       template <class H2, class P2>
       void merge(unordered_node_set<key_type, H2, P2, allocator_type>&& source)
       {
+        BOOST_ASSERT(get_allocator() == source.get_allocator());
         table_.merge(std::move(source.table_));
       }
 

include/boost/unordered/unordered_node_set_fwd.hpp

@@ -39,10 +39,6 @@ namespace boost {
   } // namespace unordered
 
   using boost::unordered::unordered_node_set;
-
-  using boost::unordered::swap;
-  using boost::unordered::operator==;
-  using boost::unordered::operator!=;
 } // namespace boost
 
 #endif

include/boost/unordered/unordered_set_fwd.hpp

@@ -58,11 +58,8 @@ namespace boost {
     template <class Iter, class NodeType> struct insert_return_type_set;
   } // namespace unordered
 
-  using boost::unordered::swap;
   using boost::unordered::unordered_multiset;
   using boost::unordered::unordered_set;
-  using boost::unordered::operator==;
-  using boost::unordered::operator!=;
 } // namespace boost
 
 #endif

test/helpers/test.hpp

@@ -7,6 +7,7 @@
 #define BOOST_UNORDERED_TEST_TEST_HEADER
 
 #include <boost/core/lightweight_test.hpp>
+#include <boost/core/lightweight_test_trait.hpp>
 #include <boost/preprocessor/cat.hpp>
 #include <boost/preprocessor/stringize.hpp>