[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>

.appveyor.yml

@@ -31,96 +31,126 @@ environment:
     B2_VARIANT: debug,release
 
   matrix:
-    - FLAVOR: Visual Studio 2008, 2010, 2012
+    - FLAVOR: Visual Studio 2015
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
-      B2_TOOLSET: msvc-9.0,msvc-10.0,msvc-11.0
-      B2_ADDRESS_MODEL: 32 # No 64bit support
+      B2_TOOLSET: msvc-14.0
 
-    - FLAVOR: Visual Studio 2013, 2015
-      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
-      B2_TOOLSET: msvc-12.0,msvc-14.0
-
-    - FLAVOR: Visual Studio 2017
+    - FLAVOR: Visual Studio 2017, C++14
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
-      B2_CXXSTD: 14,17
+      B2_CXXSTD: 14
       B2_TOOLSET: msvc-14.1
 
-    - FLAVOR: Visual Studio 2017
+    - FLAVOR: Visual Studio 2017, C++17
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
+      B2_CXXSTD: 17
+      B2_TOOLSET: msvc-14.1
+
+    - FLAVOR: Visual Studio 2017, C++latest
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
       B2_CXXSTD: latest
       B2_TOOLSET: msvc-14.1
 
-    - FLAVOR: cygwin (32-bit)
+    - FLAVOR: cygwin (32-bit, C++11)
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
       ADDPATH: C:\cygwin\bin;
       B2_ADDRESS_MODEL: 32
-      B2_CXXSTD: 03,11,14,1z
+      B2_CXXSTD: 11
       B2_TOOLSET: gcc
 
-    - FLAVOR: cygwin (64-bit)
+    - FLAVOR: cygwin (32-bit, C++14)
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
-      ADDPATH: C:\cygwin64\bin;
-      B2_ADDRESS_MODEL: 64
-      B2_CXXSTD: 03,11,14,1z
+      ADDPATH: C:\cygwin\bin;
+      B2_ADDRESS_MODEL: 32
+      B2_CXXSTD: 14
       B2_TOOLSET: gcc
 
-    - FLAVOR: cygwin (64-bit, latest)
-      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2022
-      ADDPATH: C:\cygwin64\bin;
-      B2_ADDRESS_MODEL: 64
-      B2_CXXSTD: 03
+    - FLAVOR: cygwin (32-bit, C++1z)
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
+      ADDPATH: C:\cygwin\bin;
+      B2_ADDRESS_MODEL: 32
+      B2_CXXSTD: 1z
       B2_TOOLSET: gcc
-      B2_FLAGS: "include=libs/unordered/test/unordered include=libs/unordered/test/exception"
 
-    - FLAVOR: cygwin (64-bit, latest)
+    - FLAVOR: cygwin (64-bit, latest, C++11)
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2022
       ADDPATH: C:\cygwin64\bin;
       B2_ADDRESS_MODEL: 64
       B2_CXXSTD: 11
       B2_TOOLSET: gcc
       B2_FLAGS: "include=libs/unordered/test/unordered include=libs/unordered/test/exception"
+      B2_VARIANT: release
 
-    - FLAVOR: cygwin (64-bit, latest)
+    - FLAVOR: cygwin (64-bit, latest, C++14)
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2022
       ADDPATH: C:\cygwin64\bin;
       B2_ADDRESS_MODEL: 64
       B2_CXXSTD: 14
       B2_TOOLSET: gcc
       B2_FLAGS: "include=libs/unordered/test/unordered include=libs/unordered/test/exception"
+      B2_VARIANT: release
 
-    - FLAVOR: cygwin (64-bit, latest)
+    - FLAVOR: cygwin (64-bit, latest, C++1z)
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2022
       ADDPATH: C:\cygwin64\bin;
       B2_ADDRESS_MODEL: 64
       B2_CXXSTD: 1z
       B2_TOOLSET: gcc
       B2_FLAGS: "include=libs/unordered/test/unordered include=libs/unordered/test/exception"
+      B2_VARIANT: release
 
-    - FLAVOR: mingw-w64, 32 bit
+    - FLAVOR: mingw-w64, 32 bit, C++11
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
       ADDPATH: C:\mingw-w64\i686-8.1.0-posix-dwarf-rt_v6-rev0\mingw32\bin;
-      B2_CXXSTD: 03,11,14
+      B2_CXXSTD: 11
       B2_TOOLSET: gcc
       B2_ADDRESS_MODEL: 32
 
-    - FLAVOR: mingw-w64, 32 bit
+    - FLAVOR: mingw-w64, 32 bit, C++14
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
       ADDPATH: C:\mingw-w64\i686-8.1.0-posix-dwarf-rt_v6-rev0\mingw32\bin;
-      B2_CXXSTD: 17,2a
+      B2_CXXSTD: 14
       B2_TOOLSET: gcc
       B2_ADDRESS_MODEL: 32
 
-    - FLAVOR: mingw-w64, 64 bit
+    - FLAVOR: mingw-w64, 32 bit, C++17
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
+      ADDPATH: C:\mingw-w64\i686-8.1.0-posix-dwarf-rt_v6-rev0\mingw32\bin;
+      B2_CXXSTD: 17
+      B2_TOOLSET: gcc
+      B2_ADDRESS_MODEL: 32
+
+    - FLAVOR: mingw-w64, 32 bit, C++2a
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
+      ADDPATH: C:\mingw-w64\i686-8.1.0-posix-dwarf-rt_v6-rev0\mingw32\bin;
+      B2_CXXSTD: 2a
+      B2_TOOLSET: gcc
+      B2_ADDRESS_MODEL: 32
+
+    - FLAVOR: mingw-w64, 64 bit, C++11
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
       ADDPATH: C:\mingw-w64\x86_64-8.1.0-posix-seh-rt_v6-rev0\mingw64\bin;
-      B2_CXXSTD: 03,11,14
+      B2_CXXSTD: 11
       B2_TOOLSET: gcc
       B2_ADDRESS_MODEL: 64
 
-    - FLAVOR: mingw-w64, 64 bit
+    - FLAVOR: mingw-w64, 64 bit, C++14
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
       ADDPATH: C:\mingw-w64\x86_64-8.1.0-posix-seh-rt_v6-rev0\mingw64\bin;
-      B2_CXXSTD: 17,2a
+      B2_CXXSTD: 14
+      B2_TOOLSET: gcc
+      B2_ADDRESS_MODEL: 64
+
+    - FLAVOR: mingw-w64, 64 bit, C++17
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
+      ADDPATH: C:\mingw-w64\x86_64-8.1.0-posix-seh-rt_v6-rev0\mingw64\bin;
+      B2_CXXSTD: 17
+      B2_TOOLSET: gcc
+      B2_ADDRESS_MODEL: 64
+
+    - FLAVOR: mingw-w64, 64 bit, C++2a
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
+      ADDPATH: C:\mingw-w64\x86_64-8.1.0-posix-seh-rt_v6-rev0\mingw64\bin;
+      B2_CXXSTD: 2a
       B2_TOOLSET: gcc
       B2_ADDRESS_MODEL: 64
 

.drone.jsonnet

@@ -100,40 +100,16 @@ local windows_pipeline(name, image, environment, arch = "amd64") =
 };
 
 [
-    linux_pipeline(
-        "Linux 14.04 GCC 4.4 32/64",
-        "cppalliance/droneubuntu1404:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++-4.4', CXXSTD: '98,0x', ADDRMD: '32,64' },
-        "g++-4.4-multilib",
-        [ "ppa:ubuntu-toolchain-r/test" ],
-    ),
-
-    linux_pipeline(
-        "Linux 14.04 GCC 4.6 32/64",
-        "cppalliance/droneubuntu1404:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++-4.6', CXXSTD: '98,0x', ADDRMD: '32,64' },
-        "g++-4.6-multilib",
-        [ "ppa:ubuntu-toolchain-r/test" ],
-    ),
-
-    linux_pipeline(
-        "Linux 14.04 GCC 4.7 32/64",
-        "cppalliance/droneubuntu1404:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++-4.7', CXXSTD: '98,0x', ADDRMD: '32,64' },
-        "g++-4.7-multilib",
-        [ "ppa:ubuntu-toolchain-r/test" ],
-    ),
-
     linux_pipeline(
         "Linux 14.04 GCC 4.8* 32/64",
         "cppalliance/droneubuntu1404:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '03,11', ADDRMD: '32,64' },
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '11', ADDRMD: '32,64' },
     ),
 
     linux_pipeline(
         "Linux 14.04 GCC 4.9 32/64",
         "cppalliance/droneubuntu1404:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++-4.9', CXXSTD: '03,11', ADDRMD: '32,64' },
+        { TOOLSET: 'gcc', COMPILER: 'g++-4.9', CXXSTD: '11', ADDRMD: '32,64' },
         "g++-4.9-multilib",
         [ "ppa:ubuntu-toolchain-r/test" ],
     ),
@@ -141,87 +117,155 @@ local windows_pipeline(name, image, environment, arch = "amd64") =
     linux_pipeline(
         "Linux 16.04 GCC 5* 32/64",
         "cppalliance/droneubuntu1604:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '03,11,14', ADDRMD: '32,64' },
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '11,14', ADDRMD: '32,64' },
     ),
 
     linux_pipeline(
         "Linux 18.04 GCC 6 32/64",
         "cppalliance/droneubuntu1804:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++-6', CXXSTD: '03,11,14', ADDRMD: '32,64' },
+        { TOOLSET: 'gcc', COMPILER: 'g++-6', CXXSTD: '11,14', ADDRMD: '32,64' },
         "g++-6-multilib",
     ),
 
     linux_pipeline(
         "Linux 18.04 GCC 7* 32/64",
         "cppalliance/droneubuntu1804:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '03,11,14,17', ADDRMD: '32,64' },
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '11,14,17', ADDRMD: '32,64' },
     ),
 
     linux_pipeline(
-        "Linux 18.04 GCC 8 32/64",
+        "Linux 18.04 GCC 8 32/64 (11)",
         "cppalliance/droneubuntu1804:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++-8', CXXSTD: '03,11,14,17', ADDRMD: '32,64' },
+        { TOOLSET: 'gcc', COMPILER: 'g++-8', CXXSTD: '11', ADDRMD: '32,64' },
         "g++-8-multilib",
     ),
 
     linux_pipeline(
-        "Linux 20.04 GCC 9* 32/64",
+        "Linux 18.04 GCC 8 32/64 (14,17)",
+        "cppalliance/droneubuntu1804:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-8', CXXSTD: '14,17', ADDRMD: '32,64' },
+        "g++-8-multilib",
+    ),
+
+    linux_pipeline(
+        "Linux 20.04 GCC 9* 32/64 (11,14)",
         "cppalliance/droneubuntu2004:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '03,11,14,17,2a', ADDRMD: '32,64' },
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '11,14', ADDRMD: '32,64' },
+    ),
+
+    linux_pipeline(
+        "Linux 20.04 GCC 9* 32/64 (17,2a)",
+        "cppalliance/droneubuntu2004:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '17,2a', ADDRMD: '32,64' },
     ),
 
     linux_pipeline(
         "Linux 20.04 GCC 9* ARM64",
         "cppalliance/droneubuntu2004:multiarch",
-        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '03,11,14,17,2a' },
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '11,14,17,2a' },
         arch="arm64",
     ),
 
     linux_pipeline(
-        "Linux 20.04 GCC 9* S390x",
+        "Linux 20.04 GCC 9* S390x (11,14)",
         "cppalliance/droneubuntu2004:multiarch",
-        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '03,11,14,17,2a' },
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '11,14' },
         arch="s390x",
     ),
 
     linux_pipeline(
-        "Linux 20.04 GCC 10 32/64",
+        "Linux 20.04 GCC 9* S390x (17,2a)",
+        "cppalliance/droneubuntu2004:multiarch",
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '17,2a' },
+        arch="s390x",
+    ),
+
+    linux_pipeline(
+        "Linux 20.04 GCC 10 32/64 (11,14)",
         "cppalliance/droneubuntu2004:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++-10', CXXSTD: '03,11,14,17,20', ADDRMD: '32,64' },
+        { TOOLSET: 'gcc', COMPILER: 'g++-10', CXXSTD: '11,14', ADDRMD: '32,64' },
         "g++-10-multilib",
     ),
 
     linux_pipeline(
-        "Linux 22.04 GCC 11* 32/64",
-        "cppalliance/droneubuntu2204:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '03,11,14,17,2a', ADDRMD: '32,64' },
+        "Linux 20.04 GCC 10 32/64 (17,20)",
+        "cppalliance/droneubuntu2004:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-10', CXXSTD: '17,20', ADDRMD: '32,64' },
+        "g++-10-multilib",
     ),
 
     linux_pipeline(
-        "Linux 22.04 GCC 12 32 ASAN (03,11,14)",
+        "Linux 22.04 GCC 11* 32/64 (11,14)",
         "cppalliance/droneubuntu2204:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++-12', CXXSTD: '03,11,14', ADDRMD: '32' } + asan,
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '11,14', ADDRMD: '32,64' },
+    ),
+
+    linux_pipeline(
+        "Linux 22.04 GCC 11* 32/64 (17,2a)",
+        "cppalliance/droneubuntu2204:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '17,2a', ADDRMD: '32,64' },
+    ),
+
+    linux_pipeline(
+        "Linux 22.04 GCC 12 32 ASAN (11,14)",
+        "cppalliance/droneubuntu2204:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-12', CXXSTD: '11', ADDRMD: '32' } + asan,
         "g++-12-multilib",
     ),
 
     linux_pipeline(
-        "Linux 22.04 GCC 12 32 ASAN (17,20,2b)",
+        "Linux 22.04 GCC 12 32 ASAN (14)",
         "cppalliance/droneubuntu2204:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++-12', CXXSTD: '17,20,2b', ADDRMD: '32' } + asan,
+        { TOOLSET: 'gcc', COMPILER: 'g++-12', CXXSTD: '14', ADDRMD: '32' } + asan,
         "g++-12-multilib",
     ),
 
     linux_pipeline(
-        "Linux 22.04 GCC 12 64 ASAN (03,11,14)",
+        "Linux 22.04 GCC 12 32 ASAN (17)",
         "cppalliance/droneubuntu2204:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++-12', CXXSTD: '03,11,14', ADDRMD: '64' } + asan,
+        { TOOLSET: 'gcc', COMPILER: 'g++-12', CXXSTD: '17', ADDRMD: '32' } + asan,
         "g++-12-multilib",
     ),
 
     linux_pipeline(
-        "Linux 22.04 GCC 12 64 ASAN (17,20,2b)",
+        "Linux 22.04 GCC 12 32 ASAN (20)",
         "cppalliance/droneubuntu2204:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++-12', CXXSTD: '17,20,2b', ADDRMD: '64' } + asan,
+        { TOOLSET: 'gcc', COMPILER: 'g++-12', CXXSTD: '20', ADDRMD: '32' } + asan,
+        "g++-12-multilib",
+    ),
+
+    linux_pipeline(
+        "Linux 22.04 GCC 12 32 ASAN (2b)",
+        "cppalliance/droneubuntu2204:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-12', CXXSTD: '2b', ADDRMD: '32' } + asan,
+        "g++-12-multilib",
+    ),
+
+    linux_pipeline(
+        "Linux 22.04 GCC 12 64 ASAN (11,14)",
+        "cppalliance/droneubuntu2204:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-12', CXXSTD: '11,14', ADDRMD: '64' } + asan,
+        "g++-12-multilib",
+    ),
+
+    linux_pipeline(
+        "Linux 22.04 GCC 12 64 ASAN (17)",
+        "cppalliance/droneubuntu2204:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-12', CXXSTD: '17', ADDRMD: '64' } + asan,
+        "g++-12-multilib",
+    ),
+
+    linux_pipeline(
+        "Linux 22.04 GCC 12 64 ASAN (20)",
+        "cppalliance/droneubuntu2204:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-12', CXXSTD: '20', ADDRMD: '64' } + asan,
+        "g++-12-multilib",
+    ),
+
+    linux_pipeline(
+        "Linux 22.04 GCC 12 64 ASAN (2b)",
+        "cppalliance/droneubuntu2204:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-12', CXXSTD: '2b', ADDRMD: '64' } + asan,
         "g++-12-multilib",
     ),
 
@@ -232,122 +276,150 @@ local windows_pipeline(name, image, environment, arch = "amd64") =
         "g++-12-multilib",
     ),
 
+    linux_pipeline(
+        "Linux 23.04 GCC 13 32/64 (11,14)",
+        "cppalliance/droneubuntu2304:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-13', CXXSTD: '11,14', ADDRMD: '32,64' },
+        "g++-13 g++-13-multilib",
+    ),
+
+    linux_pipeline(
+        "Linux 23.04 GCC 13 32/64 (17,20,2b)",
+        "cppalliance/droneubuntu2304:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-13', CXXSTD: '17,20,2b', ADDRMD: '32,64' },
+        "g++-13 g++-13-multilib",
+    ),
+
     linux_pipeline(
         "Linux 16.04 Clang 3.5",
         "cppalliance/droneubuntu1604:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-3.5', CXXSTD: '03,11' },
+        { TOOLSET: 'clang', COMPILER: 'clang++-3.5', CXXSTD: '11' },
         "clang-3.5",
     ),
 
     linux_pipeline(
         "Linux 16.04 Clang 3.6",
         "cppalliance/droneubuntu1604:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-3.6', CXXSTD: '03,11,14' },
+        { TOOLSET: 'clang', COMPILER: 'clang++-3.6', CXXSTD: '11,14' },
         "clang-3.6",
     ),
 
     linux_pipeline(
         "Linux 16.04 Clang 3.7",
         "cppalliance/droneubuntu1604:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-3.7', CXXSTD: '03,11,14' },
+        { TOOLSET: 'clang', COMPILER: 'clang++-3.7', CXXSTD: '11,14' },
         "clang-3.7",
     ),
 
     linux_pipeline(
         "Linux 16.04 Clang 3.8",
         "cppalliance/droneubuntu1604:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-3.8', CXXSTD: '03,11,14' },
+        { TOOLSET: 'clang', COMPILER: 'clang++-3.8', CXXSTD: '11,14' },
         "clang-3.8",
     ),
 
     linux_pipeline(
         "Linux 18.04 Clang 3.9",
         "cppalliance/droneubuntu1804:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-3.9', CXXSTD: '03,11,14' },
+        { TOOLSET: 'clang', COMPILER: 'clang++-3.9', CXXSTD: '11,14' },
         "clang-3.9",
     ),
 
     linux_pipeline(
         "Linux 18.04 Clang 4.0",
         "cppalliance/droneubuntu1804:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-4.0', CXXSTD: '03,11,14' },
+        { TOOLSET: 'clang', COMPILER: 'clang++-4.0', CXXSTD: '11,14' },
         "clang-4.0",
     ),
 
     linux_pipeline(
         "Linux 18.04 Clang 5.0",
         "cppalliance/droneubuntu1804:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-5.0', CXXSTD: '03,11,14,1z' },
+        { TOOLSET: 'clang', COMPILER: 'clang++-5.0', CXXSTD: '11,14,1z' },
         "clang-5.0",
     ),
 
     linux_pipeline(
         "Linux 18.04 Clang 6.0",
         "cppalliance/droneubuntu1804:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-6.0', CXXSTD: '03,11,14,17' },
+        { TOOLSET: 'clang', COMPILER: 'clang++-6.0', CXXSTD: '11,14,17' },
         "clang-6.0",
     ),
 
     linux_pipeline(
         "Linux 20.04 Clang 7",
         "cppalliance/droneubuntu2004:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-7', CXXSTD: '03,11,14,17' },
+        { TOOLSET: 'clang', COMPILER: 'clang++-7', CXXSTD: '11,14,17' },
         "clang-7",
     ),
 
     linux_pipeline(
         "Linux 20.04 Clang 8",
         "cppalliance/droneubuntu2004:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-8', CXXSTD: '03,11,14,17' },
+        { TOOLSET: 'clang', COMPILER: 'clang++-8', CXXSTD: '11,14,17' },
         "clang-8",
     ),
 
     linux_pipeline(
         "Linux 20.04 Clang 9",
         "cppalliance/droneubuntu2004:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-9', CXXSTD: '03,11,14,17,2a' },
+        { TOOLSET: 'clang', COMPILER: 'clang++-9', CXXSTD: '11,14,17,2a' },
         "clang-9",
     ),
 
     linux_pipeline(
         "Linux 20.04 Clang 10",
         "cppalliance/droneubuntu2004:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-10', CXXSTD: '03,11,14,17,2a' },
+        { TOOLSET: 'clang', COMPILER: 'clang++-10', CXXSTD: '11,14,17,2a' },
         "clang-10",
     ),
 
     linux_pipeline(
         "Linux 20.04 Clang 11",
         "cppalliance/droneubuntu2004:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-11', CXXSTD: '03,11,14,17,2a' },
+        { TOOLSET: 'clang', COMPILER: 'clang++-11', CXXSTD: '11,14,17,2a' },
         "clang-11",
     ),
 
     linux_pipeline(
         "Linux 20.04 Clang 12",
         "cppalliance/droneubuntu2004:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-12', CXXSTD: '03,11,14,17,2a' },
+        { TOOLSET: 'clang', COMPILER: 'clang++-12', CXXSTD: '11,14,17,2a' },
         "clang-12",
     ),
 
     linux_pipeline(
         "Linux 22.04 Clang 13",
         "cppalliance/droneubuntu2204:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-13', CXXSTD: '03,11,14,17,20' },
+        { TOOLSET: 'clang', COMPILER: 'clang++-13', CXXSTD: '11,14,17,20' },
         "clang-13",
     ),
 
     linux_pipeline(
-        "Linux 22.04 Clang 14 UBSAN",
+        "Linux 22.04 Clang 14 UBSAN (11,14)",
         "cppalliance/droneubuntu2204:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-14', CXXSTD: '03,11,14,17,20' } + ubsan,
+        { TOOLSET: 'clang', COMPILER: 'clang++-14', CXXSTD: '11,14' } + ubsan,
         "clang-14",
     ),
 
     linux_pipeline(
-        "Linux 22.04 Clang 14 ASAN",
+        "Linux 22.04 Clang 14 UBSAN (17,20)",
         "cppalliance/droneubuntu2204:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-14', CXXSTD: '03,11,14,17,20' } + asan,
+        { TOOLSET: 'clang', COMPILER: 'clang++-14', CXXSTD: '17,20' } + ubsan,
+        "clang-14",
+    ),
+
+    linux_pipeline(
+        "Linux 22.04 Clang 14 ASAN (11,14)",
+        "cppalliance/droneubuntu2204:1",
+        { TOOLSET: 'clang', COMPILER: 'clang++-14', CXXSTD: '11,14' } + asan,
+        "clang-14",
+    ),
+
+    linux_pipeline(
+        "Linux 22.04 Clang 14 ASAN (17,20)",
+        "cppalliance/droneubuntu2204:1",
+        { TOOLSET: 'clang', COMPILER: 'clang++-14', CXXSTD: '17,20' } + asan,
         "clang-14",
     ),
 
@@ -361,19 +433,29 @@ local windows_pipeline(name, image, environment, arch = "amd64") =
     linux_pipeline(
         "Linux 22.04 Clang 15",
         "cppalliance/droneubuntu2204:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-15', CXXSTD: '03,11,14,17,20,2b' },
+        { TOOLSET: 'clang', COMPILER: 'clang++-15', CXXSTD: '11,14,17,20,2b' },
         "clang-15",
         ["deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-15 main"],
     ),
 
     macos_pipeline(
-        "MacOS 10.15 Xcode 12.2 UBSAN",
-        { TOOLSET: 'clang', COMPILER: 'clang++', CXXSTD: '03,11,14,1z' } + ubsan,
+        "MacOS 10.15 Xcode 12.2 UBSAN (11)",
+        { TOOLSET: 'clang', COMPILER: 'clang++', CXXSTD: '11' } + ubsan,
+    ),
+
+    macos_pipeline(
+        "MacOS 10.15 Xcode 12.2 UBSAN (14)",
+        { TOOLSET: 'clang', COMPILER: 'clang++', CXXSTD: '14' } + ubsan,
+    ),
+
+    macos_pipeline(
+        "MacOS 10.15 Xcode 12.2 UBSAN (1z)",
+        { TOOLSET: 'clang', COMPILER: 'clang++', CXXSTD: '1z' } + ubsan,
     ),
 
     macos_pipeline(
         "MacOS 12.4 Xcode 13.4.1 ASAN",
-        { TOOLSET: 'clang', COMPILER: 'clang++', CXXSTD: '03,11,14,1z' } + asan,
+        { TOOLSET: 'clang', COMPILER: 'clang++', CXXSTD: '11,14,1z' } + asan,
         xcode_version = "13.4.1", osx_version = "monterey", arch = "arm64",
     ),
 

.drone/drone.bat

@@ -20,4 +20,4 @@ b2 -d0 headers
 
 if not "%CXXSTD%" == "" set CXXSTD=cxxstd=%CXXSTD%
 if not "%ADDRMD%" == "" set ADDRMD=address-model=%ADDRMD%
-b2 -j3 libs/%LIBRARY%/test toolset=%TOOLSET% %CXXSTD% %ADDRMD% variant=debug,release embed-manifest-via=linker
+b2 --abbreviate-paths -j3 libs/%LIBRARY%/test toolset=%TOOLSET% %CXXSTD% %ADDRMD% variant=debug,release embed-manifest-via=linker

.github/workflows/ci.yml

@@ -32,6 +32,16 @@ env:
   CODECOV_NAME: Github Actions
 
 jobs:
+  runner-selection:
+    # runs-on: ubuntu-latest
+    runs-on: ${{ github.repository_owner == 'boostorg' && fromJSON('[ "self-hosted", "linux", "x64", "ubuntu-latest-aws" ]') || 'ubuntu-latest' }}
+    outputs:
+      labelmatrix: ${{ steps.aws_hosted_runners.outputs.labelmatrix }}
+    steps:
+      - name: AWS Hosted Runners
+        id: aws_hosted_runners
+        uses: cppalliance/aws-hosted-runners@v1.0.0
+
   posix:
     defaults:
       run:
@@ -42,50 +52,71 @@ jobs:
       matrix:
         include:
           # Linux, gcc
-          - { compiler: gcc-7,     cxxstd: '03,11,14,17',    os: ubuntu-20.04, install: 'g++-7' }
-          - { compiler: gcc-8,     cxxstd: '03,11,14,17',    os: ubuntu-20.04, install: 'g++-8' }
-          - { compiler: gcc-9,     cxxstd: '03,11,14,17',    os: ubuntu-20.04, install: 'g++-9' }
-          - { compiler: gcc-10,    cxxstd: '03,11,14,17,20', os: ubuntu-22.04, install: 'g++-10' }
-          - { compiler: gcc-11,    cxxstd: '03,11,14,17,20', os: ubuntu-22.04, install: 'g++-11' }
-          - { name: "gcc-12 w/ sanitizers (03,11,14)", sanitize: yes,
-              compiler: gcc-12,    cxxstd: '03,11,14',       os: ubuntu-22.04, ccache_key: "san1" }
-          - { name: "gcc-12 w/ sanitizers (17,20,2b)", sanitize: yes,
-              compiler: gcc-12,    cxxstd: '17,20,2b',       os: ubuntu-22.04, ccache_key: "san2" }
+          - { compiler: gcc-7,     cxxstd: '11,14,17',    os: 'ubuntu-20.04', install: 'g++-7' }
+          - { compiler: gcc-8,     cxxstd: '11,14,17',    os: 'ubuntu-20.04', install: 'g++-8' }
+          - { compiler: gcc-9,     cxxstd: '11,14,17',    os: 'ubuntu-22.04', install: 'g++-9' }
+          - { compiler: gcc-10,    cxxstd: '11,14,17,20', os: 'ubuntu-22.04', install: 'g++-10' }
+          - { compiler: gcc-11,    cxxstd: '11,14,17,20', os: 'ubuntu-22.04', install: 'g++-11' }
+          - { name: "gcc-12 w/ sanitizers (11)", sanitize: yes,
+              compiler: gcc-12,    cxxstd: '11',          os: 'ubuntu-22.04', ccache_key: "san1" }
+          - { name: "gcc-12 w/ sanitizers (14)", sanitize: yes,
+              compiler: gcc-12,    cxxstd: '14',          os: 'ubuntu-22.04', ccache_key: "san1" }
+          - { name: "gcc-12 w/ sanitizers (17)", sanitize: yes,
+              compiler: gcc-12,    cxxstd: '17',          os: 'ubuntu-22.04', ccache_key: "san2" }
+          - { name: "gcc-12 w/ sanitizers (20)", sanitize: yes,
+              compiler: gcc-12,    cxxstd: '20',          os: 'ubuntu-22.04', ccache_key: "san2" }
+          - { name: "gcc-12 w/ sanitizers (2b)", sanitize: yes,
+              compiler: gcc-12,    cxxstd: '2b',          os: 'ubuntu-22.04', ccache_key: "san2" }
           - { name: Collect coverage, coverage: yes,
-              compiler: gcc-8,     cxxstd: '03,11',          os: ubuntu-20.04, install: 'g++-8-multilib', address-model: '32,64', ccache_key: "cov" }
+              compiler: gcc-12,    cxxstd: '20',          os: 'ubuntu-22.04', install: 'g++-12-multilib', address-model: '32,64', ccache_key: "cov" }
 
-          - { name: "cfoa tsan (gcc)", cxxstd: '11,14,17,20,2b', os: ubuntu-22.04, compiler: gcc-12,
-              targets: 'libs/unordered/test//cfoa_tests', thread-sanitize: yes }
+          - { name: "cfoa tsan (gcc-12)", cxxstd: '11,14,17,20,2b', os: 'ubuntu-22.04', compiler: gcc-12,
+              targets: 'libs/unordered/test//cfoa_tests', thread-sanitize: yes, ccache_key: "tsan" }
 
           # Linux, clang, libc++
-          - { compiler: clang-7,   cxxstd: '03,11,14,17',       os: ubuntu-20.04, stdlib: libc++, install: 'clang-7 libc++-7-dev libc++abi-7-dev' }
-          - { compiler: clang-10,  cxxstd: '03,11,14,17,20',    os: ubuntu-20.04, stdlib: libc++, install: 'clang-10 libc++-10-dev libc++abi-10-dev' }
-          - { compiler: clang-11,  cxxstd: '03,11,14,17,20',    os: ubuntu-22.04, stdlib: libc++, install: 'clang-11 libc++-11-dev libc++abi-11-dev' }
-          # clang-12 doesn't work on ubuntu-22.04, the linker can't find -lunwind for some reason
-          - { name: "clang-12 w/ sanitizers (03,11,14)", sanitize: yes,
-              compiler: clang-12,  cxxstd: '03,11,14',          os: ubuntu-20.04, stdlib: libc++, install: 'clang-12 libc++-12-dev libc++abi-12-dev', ccache_key: "san1" }
-          - { name: "clang-12 w/ sanitizers (17,20,2b)", sanitize: yes,
-              compiler: clang-12,  cxxstd: '17,20,2b',          os: ubuntu-20.04, stdlib: libc++, install: 'clang-12 libc++-12-dev libc++abi-12-dev', ccache_key: "san2" }
-          - { compiler: clang-13,  cxxstd: '03,11,14,17,20,2b', os: ubuntu-22.04, stdlib: libc++, install: 'clang-13 libc++-13-dev libc++abi-13-dev' }
-          - { compiler: clang-14,  cxxstd: '03,11,14,17,20,2b', os: ubuntu-22.04, stdlib: libc++, install: 'clang-14 libc++-14-dev libc++abi-14-dev' }
+          - { compiler: clang-7,    cxxstd: '11,14,17',    os: 'ubuntu-20.04', stdlib: libc++, install: 'clang-7 libc++-7-dev libc++abi-7-dev' }
+          - { compiler: clang-10,   cxxstd: '11,14,17,20', os: 'ubuntu-20.04', stdlib: libc++, install: 'clang-10 libc++-10-dev libc++abi-10-dev' }
+          - { compiler: clang-11,   cxxstd: '11,14,17,20', os: 'ubuntu-22.04', stdlib: libc++, install: 'clang-11 libc++-11-dev libc++abi-11-dev' }
+          # clang-12 doesn't work on 'ubuntu-22.04', the linker can't find -lunwind for some reason
+          - { name: "clang-12 w/ sanitizers (11,14)", sanitize: yes,
+              compiler: clang-12,   cxxstd: '11,14',       os: 'ubuntu-20.04', stdlib: libc++, install: 'clang-12 libc++-12-dev libc++abi-12-dev', ccache_key: "san1" }
+          - { name: "clang-12 w/ sanitizers (17)", sanitize: yes,
+              compiler: clang-12,   cxxstd: '17',          os: 'ubuntu-20.04', stdlib: libc++, install: 'clang-12 libc++-12-dev libc++abi-12-dev', ccache_key: "san2" }
+          - { name: "clang-12 w/ sanitizers (20)", sanitize: yes,
+              compiler: clang-12,   cxxstd: '20',          os: 'ubuntu-20.04', stdlib: libc++, install: 'clang-12 libc++-12-dev libc++abi-12-dev', ccache_key: "san2" }
+          - { name: "clang-12 w/ sanitizers (2b)", sanitize: yes,
+              compiler: clang-12,   cxxstd: '2b',          os: 'ubuntu-20.04', stdlib: libc++, install: 'clang-12 libc++-12-dev libc++abi-12-dev', ccache_key: "san2" }
+          - { compiler: 'clang-13', cxxstd: '11,14',       os: 'ubuntu-22.04', stdlib: libc++, install: 'clang-13 libc++-13-dev libc++abi-13-dev' }
+          - { compiler: 'clang-13', cxxstd: '17,20,2b',    os: 'ubuntu-22.04', stdlib: libc++, install: 'clang-13 libc++-13-dev libc++abi-13-dev' }
 
           # not using libc++ because of https://github.com/llvm/llvm-project/issues/52771
-          - { name: "clang-14 w/ sanitizers (03,11,14)", sanitize: yes,
-              compiler: clang-14,  cxxstd: '03,11,14',          os: ubuntu-22.04, ccache_key: "san1" }
-          - { name: "clang-14 w/ sanitizers (17,20,2b)", sanitize: yes,
-              compiler: clang-14,  cxxstd: '17,20,2b',          os: ubuntu-22.04, ccache_key: "san2" }
+          - { name: "clang-14 w/ sanitizers (11,14)", sanitize: yes,
+              compiler: clang-14,  cxxstd: '11,14', os: 'ubuntu-22.04', ccache_key: "san1" }
+          - { 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',   container: 'ubuntu:22.04',  os: 'ubuntu-latest', ccache_key: "san2" }
+          - { name: "clang-14 w/ sanitizers (2b)", sanitize: yes,
+              compiler: clang-14,  cxxstd: '2b',   container: 'ubuntu:22.04',  os: 'ubuntu-latest', ccache_key: "san2" }
 
-          - { name: "cfoa tsan (clang)", cxxstd: '11,14,17,20,2b', os: ubuntu-22.04, compiler: clang-14,
-              targets: 'libs/unordered/test//cfoa_tests', thread-sanitize: yes, 
-              stdlib: libc++, install: 'clang-14 libc++-14-dev libc++abi-14-dev' }
+          - { 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,
+              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' }
+          - { compiler: 'clang-15', cxxstd: '17,20,2b', os: 'ubuntu-22.04', stdlib: libc++, install: 'clang-15 libc++-15-dev libc++abi-15-dev' }
 
           # OSX, clang
-          - { compiler: clang,     cxxstd: '03,11,14,17,2a',    os: macos-11, }
-          - { compiler: clang,     cxxstd: '03,11,14,17,2a',    os: macos-12, sanitize: yes }
-          - { compiler: clang,     cxxstd: '11,14,17,2a',       os: macos-12, thread-sanitize: yes, targets: 'libs/unordered/test//cfoa_tests' }
+          - { compiler: clang, cxxstd: '11,14,17,2a',    os: 'macos-11' }
+          - { compiler: clang, cxxstd: '11,14,17,2a',    os: 'macos-12', sanitize: yes, ccache_key: "san1" }
+          - { compiler: clang, cxxstd: '11,14,17,2a',    os: 'macos-12', thread-sanitize: yes, targets: 'libs/unordered/test//cfoa_tests', ccache_key: "tsan" }
+          - { compiler: clang, cxxstd: '11,14,17,20,2b', os: 'macos-13' }
 
-    timeout-minutes: 180
-    runs-on: ${{matrix.os}}
+    timeout-minutes: 360
+    # posix (gcc-12 w/ sanitizers is taking longer than 210 minutes
+    # timeout-minutes: 210
+    needs: [runner-selection]
+    runs-on: ${{ fromJSON(needs.runner-selection.outputs.labelmatrix)[matrix.os] }}
     container: ${{matrix.container}}
     env: {B2_USE_CCACHE: 1}
 
@@ -103,7 +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
@@ -229,15 +260,16 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - { toolset: msvc-14.0, cxxstd: '14,latest',       addrmd: '32,64', os: windows-2019, variant: 'debug,release' }
-          - { toolset: msvc-14.2, cxxstd: '14,17,20,latest', addrmd: '32,64', os: windows-2019, variant: 'debug,release' }
-          - { toolset: msvc-14.3, cxxstd: '14,17,20,latest', addrmd: '32,64', os: windows-2022, variant: 'debug,release' }
-          - { toolset: msvc-14.3, cxxstd: '14',              addrmd: '64',    os: windows-2022, variant: 'debug', defines: '_ALLOW_RTCc_IN_STL', cxxflags: '/RTCc'              }
-          - { toolset: msvc-14.3, cxxstd: '14',              addrmd: '32',    os: windows-2022, variant: 'debug', defines: '_ALLOW_RTCc_IN_STL', cxxflags: '"/RTCc /arch:IA32"' }
-          - { toolset: clang-win, cxxstd: '14,17,latest',    addrmd: '32,64', os: windows-2022, variant: 'debug,release' }
-          - { toolset: gcc,       cxxstd: '03,11,14,17,2a',  addrmd: '64',    os: windows-2019, variant: 'debug,release' }
+          - { toolset: msvc-14.0, cxxstd: '14,latest',       addrmd: '32,64', os: 'windows-2019', variant: 'debug,release' }
+          - { toolset: msvc-14.2, cxxstd: '14,17,20,latest', addrmd: '32,64', os: 'windows-2019', variant: 'debug,release' }
+          - { toolset: msvc-14.3, cxxstd: '14,17,20,latest', addrmd: '32,64', os: 'windows-2022', variant: 'debug,release' }
+          - { toolset: msvc-14.3, cxxstd: '14',              addrmd: '64',    os: 'windows-2022', variant: 'debug', defines: '_ALLOW_RTCc_IN_STL', cxxflags: '/RTCc'              }
+          - { toolset: msvc-14.3, cxxstd: '14',              addrmd: '32',    os: 'windows-2022', variant: 'debug', defines: '_ALLOW_RTCc_IN_STL', cxxflags: '"/RTCc /arch:IA32"' }
+          - { toolset: clang-win, cxxstd: '14,17,latest',    addrmd: '32,64', os: 'windows-2022', variant: 'debug,release' }
+          - { toolset: gcc,       cxxstd: '11,14,17,2a',     addrmd: '64',    os: 'windows-2019', variant: 'debug,release' }
 
-    runs-on: ${{matrix.os}}
+    needs: [runner-selection]
+    runs-on: ${{ fromJSON(needs.runner-selection.outputs.labelmatrix)[matrix.os] }}
 
     steps:
       - uses: actions/checkout@v3
@@ -291,10 +323,11 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - { sys: MINGW32, compiler: gcc, cxxstd: '03,11,17,20' }
-          - { sys: MINGW64, compiler: gcc, cxxstd: '03,11,17,20' }
+          - { sys: MINGW32, compiler: gcc, cxxstd: '11,17,20' }
+          - { sys: MINGW64, compiler: gcc, cxxstd: '11,17,20' }
 
-    runs-on: windows-latest
+    needs: [runner-selection]
+    runs-on: ${{ fromJSON(needs.runner-selection.outputs.labelmatrix)['windows-latest'] }}
 
     steps:
       - uses: actions/checkout@v3
@@ -348,11 +381,12 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - { os: ubuntu-20.04, build_shared: ON,  build_type: Debug, generator: 'Unix Makefiles' }
-          - { os: windows-2019, build_shared: ON,  build_type: Debug, generator: 'Visual Studio 16 2019' }
+          - { os: 'ubuntu-20.04', build_shared: ON,  build_type: Debug, generator: 'Unix Makefiles' }
+          - { os: 'windows-2019', build_shared: ON,  build_type: Debug, generator: 'Visual Studio 16 2019' }
 
     timeout-minutes: 120
-    runs-on: ${{matrix.os}}
+    needs: [runner-selection]
+    runs-on: ${{ fromJSON(needs.runner-selection.outputs.labelmatrix)[matrix.os] }}
 
     steps:
       - uses: actions/checkout@v3

CMakeLists.txt

@@ -22,6 +22,7 @@ target_link_libraries(boost_unordered
     Boost::mp11
     Boost::predef
     Boost::preprocessor
+    Boost::static_assert
     Boost::throw_exception
     Boost::tuple
     Boost::type_traits

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).