updated concurrent map benchmark plots

.appveyor.yml

@@ -31,14 +31,28 @@ environment:
     B2_VARIANT: debug,release
 
   matrix:
-    - FLAVOR: Visual Studio 2008, 2010, 2012
+    - FLAVOR: Visual Studio 2008
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
-      B2_TOOLSET: msvc-9.0,msvc-10.0,msvc-11.0
+      B2_TOOLSET: msvc-9.0
       B2_ADDRESS_MODEL: 32 # No 64bit support
 
-    - FLAVOR: Visual Studio 2013, 2015
+    - FLAVOR: Visual Studio 2010
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
-      B2_TOOLSET: msvc-12.0,msvc-14.0
+      B2_TOOLSET: msvc-10.0
+      B2_ADDRESS_MODEL: 32 # No 64bit support
+
+    - FLAVOR: Visual Studio 2012
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+      B2_TOOLSET: msvc-11.0
+      B2_ADDRESS_MODEL: 32 # No 64bit support
+
+    - FLAVOR: Visual Studio 2013
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+      B2_TOOLSET: msvc-12.0
+
+    - FLAVOR: Visual Studio 2015
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+      B2_TOOLSET: msvc-14.0
 
     - FLAVOR: Visual Studio 2017, C++14
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
@@ -55,32 +69,32 @@ environment:
       B2_CXXSTD: latest
       B2_TOOLSET: msvc-14.1
 
-    - FLAVOR: cygwin (32-bit, C++03,11)
+    - FLAVOR: cygwin (32-bit, C++03)
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
       ADDPATH: C:\cygwin\bin;
       B2_ADDRESS_MODEL: 32
-      B2_CXXSTD: 03,11
+      B2_CXXSTD: 03
       B2_TOOLSET: gcc
 
-    - FLAVOR: cygwin (32-bit, C++14,1z)
+    - FLAVOR: cygwin (32-bit, C++11)
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
       ADDPATH: C:\cygwin\bin;
       B2_ADDRESS_MODEL: 32
-      B2_CXXSTD: 14,1z
+      B2_CXXSTD: 11
       B2_TOOLSET: gcc
 
-    - FLAVOR: cygwin (64-bit, C++03,11)
+    - 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
+      ADDPATH: C:\cygwin\bin;
+      B2_ADDRESS_MODEL: 32
+      B2_CXXSTD: 14
       B2_TOOLSET: gcc
 
-    - FLAVOR: cygwin (64-bit, C++14,1z)
+    - FLAVOR: cygwin (32-bit, C++1z)
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
-      ADDPATH: C:\cygwin64\bin;
-      B2_ADDRESS_MODEL: 64
-      B2_CXXSTD: 14,1z
+      ADDPATH: C:\cygwin\bin;
+      B2_ADDRESS_MODEL: 32
+      B2_CXXSTD: 1z
       B2_TOOLSET: gcc
 
     - FLAVOR: cygwin (64-bit, latest, C++03)

.github/workflows/ci.yml

@@ -44,7 +44,7 @@ jobs:
           # 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-9,     cxxstd: '03,11,14,17',    os: ubuntu-22.04, 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,
@@ -54,8 +54,8 @@ jobs:
           - { name: Collect coverage, coverage: yes,
               compiler: gcc-12,     cxxstd: '03,20',          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' }
@@ -67,7 +67,6 @@ jobs:
           - { 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' }
 
           # not using libc++ because of https://github.com/llvm/llvm-project/issues/52771
           - { name: "clang-14 w/ sanitizers (03,11,14)", sanitize: yes,
@@ -75,16 +74,19 @@ jobs:
           - { 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: "cfoa tsan (clang)", cxxstd: '11,14,17,20,2b', os: ubuntu-22.04, compiler: clang-14,
+          - { 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' }
+              stdlib: libc++, install: 'clang-14 libc++-14-dev libc++abi-14-dev', ccache_key: "tsan" }
+
+          - { compiler: clang-15,  cxxstd: '03,11,14,17,20,2b', 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: '03,11,14,17,2a',    os: macos-11 }
+          - { compiler: clang,     cxxstd: '03,11,14,17,2a',    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: '03,11,14,17,20,2b', os: macos-13 }
 
-    timeout-minutes: 180
+    timeout-minutes: 210
     runs-on: ${{matrix.os}}
     container: ${{matrix.container}}
     env: {B2_USE_CCACHE: 1}

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

@@ -17,10 +17,13 @@
 #include <boost/core/ignore_unused.hpp>
 #include <boost/core/no_exceptions_support.hpp>
 #include <boost/cstdint.hpp>
+#include <boost/mp11/algorithm.hpp>
+#include <boost/mp11/list.hpp>
 #include <boost/mp11/tuple.hpp>
 #include <boost/static_assert.hpp>
 #include <boost/unordered/detail/foa/core.hpp>
 #include <boost/unordered/detail/foa/rw_spinlock.hpp>
+#include <boost/unordered/detail/foa/takes_arg_as_const_reference.hpp>
 #include <boost/unordered/detail/foa/tuple_rotate_right.hpp>
 #include <cstddef>
 #include <functional>
@@ -485,7 +488,7 @@ public:
   template<typename Key,typename F>
   BOOST_FORCEINLINE std::size_t visit(const Key& x,F&& f)
   {
-    return visit_impl(group_exclusive{},x,std::forward<F>(f));
+    return visit_impl(group_access_for<F>{},x,std::forward<F>(f));
   }
 
   template<typename Key,typename F>
@@ -502,7 +505,7 @@ public:
 
   template<typename F> std::size_t visit_all(F&& f)
   {
-    return visit_all_impl(group_exclusive{},std::forward<F>(f));
+    return visit_all_impl(group_access_for<F>{},std::forward<F>(f));
   }
 
   template<typename F> std::size_t visit_all(F&& f)const
@@ -520,7 +523,7 @@ public:
   void visit_all(ExecutionPolicy&& policy,F&& f)
   {
     visit_all_impl(
-      group_exclusive{},
+      group_access_for<F>{},
       std::forward<ExecutionPolicy>(policy),std::forward<F>(f));
   }
 
@@ -582,7 +585,7 @@ public:
   BOOST_FORCEINLINE bool try_emplace_or_visit(Key&& x,Args&&... args)
   {
     return emplace_or_visit_flast(
-      group_exclusive{},
+      group_access_for_last_of<Args...>{},
       try_emplace_args_t{},std::forward<Key>(x),std::forward<Args>(args)...);
   }
 
@@ -598,7 +601,7 @@ public:
   BOOST_FORCEINLINE bool emplace_or_visit(Args&&... args)
   {
     return construct_and_emplace_or_visit_flast(
-      group_exclusive{},std::forward<Args>(args)...);
+      group_access_for_last_of<Args...>{},std::forward<Args>(args)...);
   }
 
   template<typename... Args>
@@ -611,7 +614,7 @@ public:
   template<typename F>
   BOOST_FORCEINLINE bool insert_or_visit(const init_type& x,F&& f)
   {
-    return emplace_or_visit_impl(group_exclusive{},std::forward<F>(f),x);
+    return emplace_or_visit_impl(group_access_for<F>{},std::forward<F>(f),x);
   }
 
   template<typename F>
@@ -624,7 +627,7 @@ public:
   BOOST_FORCEINLINE bool insert_or_visit(init_type&& x,F&& f)
   {
     return emplace_or_visit_impl(
-      group_exclusive{},std::forward<F>(f),std::move(x));
+      group_access_for<F>{},std::forward<F>(f),std::move(x));
   }
 
   template<typename F>
@@ -640,7 +643,7 @@ public:
   BOOST_FORCEINLINE auto insert_or_visit(const Value& x,F&& f)
     ->enable_if_is_value_type<Value,bool>
   {
-    return emplace_or_visit_impl(group_exclusive{},std::forward<F>(f),x);
+    return emplace_or_visit_impl(group_access_for<F>{},std::forward<F>(f),x);
   }
 
   template<typename Value,typename F>
@@ -655,7 +658,7 @@ public:
     ->enable_if_is_value_type<Value,bool>
   {
     return emplace_or_visit_impl(
-      group_exclusive{},std::forward<F>(f),std::move(x));
+      group_access_for<F>{},std::forward<F>(f),std::move(x));
   }
 
   template<typename Value,typename F>
@@ -683,7 +686,7 @@ public:
       group_exclusive{},x,this->position_for(hash),hash,
       [&,this](group_type* pg,unsigned int n,element_type* p)
       {
-        if(f(cast_for(group_exclusive{},type_policy::value_from(*p)))){
+        if(f(cast_for(group_access_for<F>{},type_policy::value_from(*p)))){
           super::erase(pg,n,p);
           res=1;
         }
@@ -699,7 +702,7 @@ public:
     for_all_elements(
       group_exclusive{},
       [&,this](group_type* pg,unsigned int n,element_type* p){
-        if(f(cast_for(group_exclusive{},type_policy::value_from(*p)))){
+        if(f(cast_for(group_access_for<F>{},type_policy::value_from(*p)))){
           super::erase(pg,n,p);
           ++res;
         }
@@ -716,7 +719,7 @@ public:
     for_all_elements(
       group_exclusive{},std::forward<ExecutionPolicy>(policy),
       [&,this](group_type* pg,unsigned int n,element_type* p){
-        if(f(cast_for(group_exclusive{},type_policy::value_from(*p)))){
+        if(f(cast_for(group_access_for<F>{},type_policy::value_from(*p)))){
           super::erase(pg,n,p);
         }
       });
@@ -886,6 +889,17 @@ private:
   using group_shared=std::false_type;
   using group_exclusive=std::true_type;
 
+  template<typename F>
+  using group_access_for=typename std::conditional<
+    takes_arg_as_const_reference<F,value_type>::value,
+    group_shared,
+    group_exclusive
+  >::type;
+
+  template<typename... Args>
+  using group_access_for_last_of=
+    group_access_for<mp11::mp_back<mp11::mp_list<Args...>>>;
+
   inline group_shared_lock_guard access(group_shared,std::size_t pos)const
   {
     return this->arrays.group_accesses[pos].shared_access();

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

@@ -0,0 +1,98 @@
+/* Copyright 2023 Joaquin M Lopez Munoz.
+ * Distributed under the Boost Software License, Version 1.0.
+ * (See accompanying file LICENSE_1_0.txt or copy at
+ * http://www.boost.org/LICENSE_1_0.txt)
+ *
+ * See https://www.boost.org/libs/unordered for library home page.
+ */
+
+#ifndef BOOST_UNORDERED_DETAIL_FOA_TAKES_ARG_AS_CONST_REFERENCE_HPP
+#define BOOST_UNORDERED_DETAIL_FOA_TAKES_ARG_AS_CONST_REFERENCE_HPP
+
+#include <boost/type_traits/make_void.hpp>
+#include <type_traits>
+#include <utility>
+
+namespace boost{
+namespace unordered{
+namespace detail{
+namespace foa{
+
+template<typename Arg,typename R,typename... Args>
+void check_function_1st_arg(R(*)(Arg,Args...));
+
+template<typename Arg,typename R,typename... Args>
+void check_function_1st_arg(R(*)(Arg,Args...,...));
+
+#define BOOST_UNORDERED_CHECK_MEMFUN_1ST_ARG(qualifier)       \
+template<typename Arg,typename R,typename C,typename... Args> \
+void check_memfun_1st_arg(R(C::*)(Arg,Args...)qualifier);     \
+                                                              \
+template<typename Arg,typename R,typename C,typename... Args> \
+void check_memfun_1st_arg(R(C::*)(Arg,Args...,...)qualifier);
+
+/* VS warns when a pp function is directly called with an empty arg */
+#define BOOST_UNORDERED_EMPTY_PP_ARG()
+
+BOOST_UNORDERED_CHECK_MEMFUN_1ST_ARG(BOOST_UNORDERED_EMPTY_PP_ARG())
+BOOST_UNORDERED_CHECK_MEMFUN_1ST_ARG(const)
+BOOST_UNORDERED_CHECK_MEMFUN_1ST_ARG(volatile)
+BOOST_UNORDERED_CHECK_MEMFUN_1ST_ARG(const volatile)
+BOOST_UNORDERED_CHECK_MEMFUN_1ST_ARG(&)
+BOOST_UNORDERED_CHECK_MEMFUN_1ST_ARG(const&)
+BOOST_UNORDERED_CHECK_MEMFUN_1ST_ARG(volatile&)
+BOOST_UNORDERED_CHECK_MEMFUN_1ST_ARG(const volatile&)
+BOOST_UNORDERED_CHECK_MEMFUN_1ST_ARG(&&)
+BOOST_UNORDERED_CHECK_MEMFUN_1ST_ARG(const&&)
+BOOST_UNORDERED_CHECK_MEMFUN_1ST_ARG(volatile&&)
+BOOST_UNORDERED_CHECK_MEMFUN_1ST_ARG(const volatile&&)
+
+#undef BOOST_UNORDERED_EMPTY_PP_ARG
+#undef BOOST_UNORDERED_CHECK_MEMFUN_1ST_ARG
+
+/* Detects if f(x) takes x as a const reference. From an implementation
+ * technique by Kenneth Gorking.
+ * Requires: F is invocable with an Arg&.
+ */
+
+template<typename F,typename Arg,typename=void>
+struct takes_arg_as_const_reference0:std::false_type{};
+
+template<typename F,typename Arg>
+struct takes_arg_as_const_reference0<
+  F,Arg,
+  decltype(check_function_1st_arg<const Arg&>(std::declval<F>()))
+>:std::true_type{};
+
+template<typename F,typename Arg>
+struct takes_arg_as_const_reference0<
+  F,Arg,
+  boost::void_t<
+    decltype(std::declval<F>().operator()(std::declval<Arg&>()))
+  >
+>:std::true_type{};
+
+template<typename F,typename Arg,typename=void>
+struct takes_arg_as_const_reference:takes_arg_as_const_reference0<F,Arg>{};
+
+template<
+  typename F,typename Arg,
+  typename R=decltype(std::declval<F>()(std::declval<Arg&>())),
+  typename RawF=
+    typename std::remove_cv<typename std::remove_reference<F>::type>::type
+>
+decltype(check_memfun_1st_arg<Arg&,R,RawF>(&RawF::operator()))
+check_operator_call_takes_arg_as_reference();
+
+template<typename F,typename Arg>
+struct takes_arg_as_const_reference<
+  F,Arg,
+  decltype(check_operator_call_takes_arg_as_reference<F,Arg>())
+>:std::false_type{};
+
+} /* namespace foa */
+} /* namespace detail */
+} /* namespace unordered */
+} /* namespace boost */
+
+#endif

test/CMakeLists.txt

@@ -20,7 +20,7 @@ function(foa_tests)
 endfunction()
 
 function(cfoa_tests)
-  boost_test(PREFIX boost_unordered_cfoa LINK_LIBRARIES Threads::Threads ${ARGN})
+  boost_test(PREFIX boost_unordered_cfoa LINK_LIBRARIES Boost::compat Threads::Threads ${ARGN})
 endfunction()
 
 # FCA tests
@@ -140,7 +140,6 @@ foa_tests(SOURCES exception/merge_exception_tests.cpp)
 
 # CFOA tests
 
-cfoa_tests(SOURCES cfoa/latch_tests.cpp)
 cfoa_tests(SOURCES cfoa/insert_tests.cpp)
 cfoa_tests(SOURCES cfoa/erase_tests.cpp)
 cfoa_tests(SOURCES cfoa/try_emplace_tests.cpp)
@@ -159,5 +158,13 @@ cfoa_tests(SOURCES cfoa/exception_erase_tests.cpp)
 cfoa_tests(SOURCES cfoa/exception_constructor_tests.cpp)
 cfoa_tests(SOURCES cfoa/exception_assign_tests.cpp)
 cfoa_tests(SOURCES cfoa/exception_merge_tests.cpp)
+cfoa_tests(SOURCES cfoa/rw_spinlock_test.cpp)
+cfoa_tests(SOURCES cfoa/rw_spinlock_test2.cpp)
+cfoa_tests(SOURCES cfoa/rw_spinlock_test3.cpp)
+cfoa_tests(SOURCES cfoa/rw_spinlock_test4.cpp)
+cfoa_tests(SOURCES cfoa/rw_spinlock_test5.cpp)
+cfoa_tests(SOURCES cfoa/rw_spinlock_test6.cpp)
+cfoa_tests(SOURCES cfoa/rw_spinlock_test7.cpp)
+cfoa_tests(SOURCES cfoa/rw_spinlock_test8.cpp)
 
 endif()

test/Jamfile.v2

@@ -176,7 +176,6 @@ alias foa_tests :
 ;
 
 local CFOA_TESTS =
-  latch_tests
   insert_tests
   erase_tests
   try_emplace_tests
@@ -195,6 +194,15 @@ local CFOA_TESTS =
   exception_constructor_tests
   exception_assign_tests
   exception_merge_tests
+  rw_spinlock_test
+  rw_spinlock_test2
+  rw_spinlock_test3
+  rw_spinlock_test4
+  rw_spinlock_test5
+  rw_spinlock_test6
+  rw_spinlock_test7
+  rw_spinlock_test8
+  takes_arg_as_cref_tests
 ;
 
 for local test in $(CFOA_TESTS)

test/cfoa/assign_tests.cpp

@@ -787,7 +787,7 @@ namespace {
 
     std::thread t1, t2, t3;
 
-    boost::latch start_latch(2), end_latch(2);
+    boost::compat::latch start_latch(2), end_latch(2);
 
     auto v1 = make_random_values(1024 * 16, [&] { return gen(rg); });
     auto v2 = v1;

test/cfoa/exception_helpers.hpp

@@ -2,11 +2,10 @@
 // Distributed under the Boost Software License, Version 1.0. (See accompanying
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 
-#include "latch.hpp"
-
 #include "../helpers/generators.hpp"
 #include "../helpers/test.hpp"
 
+#include <boost/compat/latch.hpp>
 #include <boost/container_hash/hash.hpp>
 #include <boost/core/span.hpp>
 #include <boost/unordered/unordered_flat_map.hpp>
@@ -370,7 +369,7 @@ std::vector<boost::span<T> > split(
 
 template <class T, class F> void thread_runner(std::vector<T>& values, F f)
 {
-  boost::latch latch(static_cast<std::ptrdiff_t>(num_threads));
+  boost::compat::latch latch(static_cast<std::ptrdiff_t>(num_threads));
 
   std::vector<std::thread> threads;
   auto subslices = split<T>(values, num_threads);

test/cfoa/helpers.hpp

@@ -5,11 +5,10 @@
 #ifndef BOOST_UNORDERED_TEST_CFOA_HELPERS_HPP
 #define BOOST_UNORDERED_TEST_CFOA_HELPERS_HPP
 
-#include "latch.hpp"
-
 #include "../helpers/generators.hpp"
 #include "../helpers/test.hpp"
 
+#include <boost/compat/latch.hpp>
 #include <boost/container_hash/hash.hpp>
 #include <boost/core/span.hpp>
 #include <boost/unordered/unordered_flat_map.hpp>
@@ -339,7 +338,7 @@ std::vector<boost::span<T> > split(
 
 template <class T, class F> void thread_runner(std::vector<T>& values, F f)
 {
-  boost::latch latch(static_cast<std::ptrdiff_t>(num_threads));
+  boost::compat::latch latch(static_cast<std::ptrdiff_t>(num_threads));
 
   std::vector<std::thread> threads;
   auto subslices = split<T>(values, num_threads);

test/cfoa/latch.hpp

@@ -1,87 +0,0 @@
-// Copyright (C) 2023 Christian Mazakas
-// Distributed under the Boost Software License, Version 1.0. (See accompanying
-// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-
-#ifndef BOOST_UNORDERED_TEST_CFOA_LATCH_HPP
-#define BOOST_UNORDERED_TEST_CFOA_LATCH_HPP
-
-#include <boost/assert.hpp>
-
-#include <climits>
-#include <condition_variable>
-#include <cstddef>
-#include <mutex>
-
-namespace boost {
-  class latch
-  {
-  private:
-    std::ptrdiff_t n_;
-    mutable std::mutex m_;
-    mutable std::condition_variable cv_;
-
-  public:
-    explicit latch(std::ptrdiff_t expected) : n_{expected}, m_{}, cv_{}
-    {
-      BOOST_ASSERT(n_ >= 0);
-      BOOST_ASSERT(n_ <= max());
-    }
-
-    latch(latch const&) = delete;
-    latch& operator=(latch const&) = delete;
-
-    ~latch() = default;
-
-    void count_down(std::ptrdiff_t n = 1)
-    {
-      std::unique_lock<std::mutex> lk(m_);
-      count_down_and_notify(lk, n);
-    }
-
-    bool try_wait() const noexcept
-    {
-      std::unique_lock<std::mutex> lk(m_);
-      return is_ready();
-    }
-
-    void wait() const
-    {
-      std::unique_lock<std::mutex> lk(m_);
-      wait_impl(lk);
-    }
-
-    void arrive_and_wait(std::ptrdiff_t n = 1)
-    {
-      std::unique_lock<std::mutex> lk(m_);
-      bool should_wait = count_down_and_notify(lk, n);
-      if (should_wait) {
-        wait_impl(lk);
-      }
-    }
-
-    static constexpr std::ptrdiff_t max() noexcept { return INT_MAX; }
-
-  private:
-    bool is_ready() const { return n_ == 0; }
-
-    bool count_down_and_notify(
-      std::unique_lock<std::mutex>& lk, std::ptrdiff_t n)
-    {
-      n_ -= n;
-      if (n_ == 0) {
-        lk.unlock();
-        cv_.notify_all();
-        return false;
-      }
-
-      return true;
-    }
-
-    void wait_impl(std::unique_lock<std::mutex>& lk) const
-    {
-      cv_.wait(lk, [this] { return this->is_ready(); });
-    }
-  };
-} // namespace boost
-
-#endif // BOOST_UNORDERED_TEST_CFOA_LATCH_HPP

test/cfoa/latch_tests.cpp

@@ -1,155 +0,0 @@
-// Copyright (C) 2023 Christian Mazakas
-// Distributed under the Boost Software License, Version 1.0. (See accompanying
-// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-
-#define BOOST_ENABLE_ASSERT_HANDLER
-
-#include "latch.hpp"
-
-#include <boost/core/lightweight_test.hpp>
-
-#include <thread>
-#include <vector>
-
-struct exception
-{
-};
-
-namespace boost {
-  void assertion_failed(
-    char const* expr, char const* function, char const* file, long line)
-  {
-    (void)expr;
-    (void)function;
-    (void)file;
-    (void)line;
-    throw exception{};
-  }
-} // namespace boost
-
-namespace {
-  void test_max() { BOOST_TEST_EQ(boost::latch::max(), INT_MAX); }
-
-  void test_constructor()
-  {
-    {
-      auto const f = [] {
-        boost::latch l(-1);
-        (void)l;
-      };
-      BOOST_TEST_THROWS(f(), exception);
-    }
-
-    {
-      std::ptrdiff_t n = 0;
-
-      boost::latch l(n);
-      BOOST_TEST(l.try_wait());
-    }
-
-    {
-      std::ptrdiff_t n = 16;
-
-      boost::latch l(n);
-      BOOST_TEST_NOT(l.try_wait());
-
-      l.count_down(16);
-      BOOST_TEST(l.try_wait());
-    }
-
-#if PTRDIFF_MAX > INT_MAX
-    {
-      auto const f = [] {
-        std::ptrdiff_t n = INT_MAX;
-        n += 10;
-        boost::latch l(n);
-        (void)l;
-      };
-      BOOST_TEST_THROWS(f(), exception);
-    }
-#endif
-  }
-
-  void test_count_down_and_wait()
-  {
-    constexpr std::ptrdiff_t n = 1024;
-
-    boost::latch l(2 * n);
-
-    bool bs[] = {false, false};
-
-    std::thread t1([&] {
-      l.wait();
-      BOOST_TEST(bs[0]);
-      BOOST_TEST(bs[1]);
-    });
-
-    std::thread t2([&] {
-      for (int i = 0; i < n; ++i) {
-        if (i == (n - 1)) {
-          bs[0] = true;
-        } else {
-          BOOST_TEST_NOT(l.try_wait());
-        }
-
-        l.count_down(1);
-      }
-    });
-
-    for (int i = 0; i < n; ++i) {
-      if (i == (n - 1)) {
-        bs[1] = true;
-      } else {
-        BOOST_TEST_NOT(l.try_wait());
-      }
-
-      l.count_down(1);
-    }
-
-    t1.join();
-    t2.join();
-
-    BOOST_TEST(l.try_wait());
-  }
-
-  void test_arrive_and_wait()
-  {
-    std::ptrdiff_t const n = 16;
-
-    boost::latch l(2 * n);
-
-    int xs[n] = {0};
-
-    std::vector<std::thread> threads;
-    for (int i = 0; i < n; ++i) {
-      threads.emplace_back([&l, &xs, i, n] {
-        (void)n;
-        for (int j = 0; j < n; ++j) {
-          BOOST_TEST_EQ(xs[j], 0);
-        }
-
-        l.arrive_and_wait(2);
-
-        xs[i] = 1;
-      });
-    }
-
-    for (auto& t : threads) {
-      t.join();
-    }
-
-    for (int i = 0; i < n; ++i) {
-      BOOST_TEST_EQ(xs[i], 1);
-    }
-  }
-} // namespace
-
-int main()
-{
-  test_max();
-  test_constructor();
-  test_count_down_and_wait();
-  test_arrive_and_wait();
-
-  return boost::report_errors();
-}

test/cfoa/merge_tests.cpp

@@ -103,7 +103,7 @@ namespace {
       map2_type x2(2 * vals1.size(), allocator_type(3));
 
       std::thread t1, t2, t3;
-      boost::latch l(2);
+      boost::compat::latch l(2);
 
       std::mutex m;
       std::condition_variable cv;

test/cfoa/rehash_tests.cpp

@@ -79,7 +79,7 @@ namespace {
       map_type x(0, hasher(1), key_equal(2), allocator_type(3));
 
       std::thread t1, t2, t3;
-      boost::latch l(2);
+      boost::compat::latch l(2);
 
       std::mutex m;
       std::condition_variable cv;

test/cfoa/rw_spinlock_test.cpp

@@ -0,0 +1,26 @@
+// Copyright 2023 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/unordered/detail/foa/rw_spinlock.hpp>
+#include <mutex>
+
+using boost::unordered::detail::foa::rw_spinlock;
+
+// Sanity check only
+
+static rw_spinlock sp;
+static rw_spinlock sp2;
+
+int main()
+{
+    sp.lock();
+    sp2.lock();
+    sp.unlock();
+    sp2.unlock();
+
+    {
+        std::lock_guard<rw_spinlock> lock( sp );
+        std::lock_guard<rw_spinlock> lock2( sp2 );
+    }
+}

test/cfoa/rw_spinlock_test2.cpp

@@ -0,0 +1,41 @@
+// Copyright 2023 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/unordered/detail/foa/rw_spinlock.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <mutex>
+
+using boost::unordered::detail::foa::rw_spinlock;
+
+static rw_spinlock sp;
+static rw_spinlock sp2;
+
+int main()
+{
+    BOOST_TEST( sp.try_lock() );
+    BOOST_TEST( !sp.try_lock() );
+    BOOST_TEST( sp2.try_lock() );
+    BOOST_TEST( !sp.try_lock() );
+    BOOST_TEST( !sp2.try_lock() );
+    sp.unlock();
+    sp2.unlock();
+
+    sp.lock();
+    BOOST_TEST( !sp.try_lock() );
+    sp2.lock();
+    BOOST_TEST( !sp.try_lock() );
+    BOOST_TEST( !sp2.try_lock() );
+    sp.unlock();
+    sp2.unlock();
+
+    {
+        std::lock_guard<rw_spinlock> lock( sp );
+        BOOST_TEST( !sp.try_lock() );
+        std::lock_guard<rw_spinlock> lock2( sp2 );
+        BOOST_TEST( !sp.try_lock() );
+        BOOST_TEST( !sp2.try_lock() );
+    }
+
+    return boost::report_errors();
+}

test/cfoa/rw_spinlock_test3.cpp

@@ -0,0 +1,49 @@
+// Copyright 2023 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/unordered/detail/foa/rw_spinlock.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <mutex>
+#include <thread>
+#include <cstdio>
+
+using boost::unordered::detail::foa::rw_spinlock;
+
+static int count = 0;
+static rw_spinlock sp;
+
+void f( int k, int n )
+{
+    std::printf( "Thread %d started.\n", k );
+
+    for( int i = 0; i < n; ++i )
+    {
+        std::lock_guard<rw_spinlock> lock( sp );
+        ++count;
+    }
+
+    std::printf( "Thread %d finished.\n", k );
+}
+
+int main()
+{
+    int const N = 1000000; // iterations
+    int const M = 8;       // threads
+
+    std::thread th[ M ];
+
+    for( int i = 0; i < M; ++i )
+    {
+        th[ i ] = std::thread( f, i, N );
+    }
+
+    for( int i = 0; i < M; ++i )
+    {
+        th[ i ].join();
+    }
+
+    BOOST_TEST_EQ( count, N * M );
+
+    return boost::report_errors();
+}

test/cfoa/rw_spinlock_test4.cpp

@@ -0,0 +1,29 @@
+// Copyright 2023 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/unordered/detail/foa/rw_spinlock.hpp>
+#include <boost/compat/shared_lock.hpp>
+#include <mutex>
+
+using boost::unordered::detail::foa::rw_spinlock;
+
+static rw_spinlock sp;
+static rw_spinlock sp2;
+
+int main()
+{
+    sp.lock();
+    sp2.lock_shared();
+    sp2.lock_shared();
+
+    sp.unlock();
+    sp2.unlock_shared();
+    sp2.unlock_shared();
+
+    {
+        std::lock_guard<rw_spinlock> lock( sp );
+        boost::compat::shared_lock<rw_spinlock> lock2( sp2 );
+        boost::compat::shared_lock<rw_spinlock> lock3( sp2 );
+    }
+}

test/cfoa/rw_spinlock_test5.cpp

@@ -0,0 +1,42 @@
+// Copyright 2023 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/unordered/detail/foa/rw_spinlock.hpp>
+#include <boost/compat/shared_lock.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <mutex>
+
+using boost::unordered::detail::foa::rw_spinlock;
+
+static rw_spinlock sp;
+
+int main()
+{
+    {
+        BOOST_TEST( sp.try_lock_shared() );
+        BOOST_TEST( sp.try_lock_shared() );
+        sp.unlock_shared();
+        sp.unlock_shared();
+    }
+
+    {
+        BOOST_TEST( sp.try_lock() );
+        BOOST_TEST( !sp.try_lock_shared() );
+        sp.unlock();
+    }
+
+    {
+        std::lock_guard<rw_spinlock> lock( sp );
+        BOOST_TEST( !sp.try_lock_shared() );
+    }
+
+    {
+        boost::compat::shared_lock<rw_spinlock> lock( sp );
+        BOOST_TEST( !sp.try_lock() );
+        BOOST_TEST( sp.try_lock_shared() );
+        sp.unlock_shared();
+    }
+
+    return boost::report_errors();
+}

test/cfoa/rw_spinlock_test6.cpp

@@ -0,0 +1,60 @@
+// Copyright 2023 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/unordered/detail/foa/rw_spinlock.hpp>
+#include <boost/compat/shared_lock.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <mutex>
+#include <thread>
+#include <cstdio>
+
+using boost::unordered::detail::foa::rw_spinlock;
+
+static int count = 0;
+static rw_spinlock sp;
+
+void f( int k, int n )
+{
+    std::printf( "Thread %d started.\n", k );
+
+    int i = 0;
+
+    for( ;; ++i )
+    {
+        {
+            boost::compat::shared_lock<rw_spinlock> lock( sp );
+            if( count >= n ) break;
+        }
+
+        {
+            std::lock_guard<rw_spinlock> lock( sp );
+            if( count >= n ) break;
+            ++count;
+        }
+    }
+
+    std::printf( "Thread %d finished (%i iterations).\n", k, i );
+}
+
+int main()
+{
+    int const N = 1000000; // total iterations
+    int const M = 8;       // threads
+
+    std::thread th[ M ];
+
+    for( int i = 0; i < M; ++i )
+    {
+        th[ i ] = std::thread( f, i, N );
+    }
+
+    for( int i = 0; i < M; ++i )
+    {
+        th[ i ].join();
+    }
+
+    BOOST_TEST_EQ( count, N );
+
+    return boost::report_errors();
+}

test/cfoa/rw_spinlock_test7.cpp

@@ -0,0 +1,62 @@
+// Copyright 2023 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/unordered/detail/foa/rw_spinlock.hpp>
+#include <boost/compat/shared_lock.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <mutex>
+#include <thread>
+#include <cstdio>
+
+using boost::unordered::detail::foa::rw_spinlock;
+
+static int count = 0;
+static rw_spinlock sp;
+
+void f( int k, int n )
+{
+    std::printf( "Thread %d started.\n", k );
+
+    int i = 0;
+
+    for( ;; ++i )
+    {
+        int oldc;
+
+        {
+            boost::compat::shared_lock<rw_spinlock> lock( sp );
+            if( count >= n ) break;
+            oldc = count;
+        }
+
+        {
+            std::lock_guard<rw_spinlock> lock( sp );
+            if( count == oldc ) ++count;
+        }
+    }
+
+    std::printf( "Thread %d finished (%i iterations).\n", k, i );
+}
+
+int main()
+{
+    int const N = 1000000; // total iterations
+    int const M = 8;       // threads
+
+    std::thread th[ M ];
+
+    for( int i = 0; i < M; ++i )
+    {
+        th[ i ] = std::thread( f, i, N );
+    }
+
+    for( int i = 0; i < M; ++i )
+    {
+        th[ i ].join();
+    }
+
+    BOOST_TEST_EQ( count, N );
+
+    return boost::report_errors();
+}

test/cfoa/rw_spinlock_test8.cpp

@@ -0,0 +1,64 @@
+// Copyright 2023 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/unordered/detail/foa/rw_spinlock.hpp>
+#include <boost/compat/shared_lock.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <mutex>
+#include <thread>
+#include <cstdio>
+
+using boost::unordered::detail::foa::rw_spinlock;
+
+static int count = 0;
+static rw_spinlock sp;
+
+void f( int k, int m, int n )
+{
+    std::printf( "Thread %d of %d started.\n", k, m );
+
+    for( int i = 0; i < n; ++i )
+    {
+        int oldc;
+
+        for( ;; )
+        {
+            {
+                boost::compat::shared_lock<rw_spinlock> lock( sp );
+                oldc = count;
+            }
+
+            if( oldc % m == k ) break;
+        }
+
+        {
+            std::lock_guard<rw_spinlock> lock( sp );
+            if( count == oldc ) ++count;
+        }
+    }
+
+    std::printf( "Thread %d of %d finished.\n", k, m );
+}
+
+int main()
+{
+    int const N = 100;    // total iterations
+    int const M = 4;      // threads
+
+    std::thread th[ M ];
+
+    for( int i = 0; i < M; ++i )
+    {
+        th[ i ] = std::thread( f, i, M, N );
+    }
+
+    for( int i = 0; i < M; ++i )
+    {
+        th[ i ].join();
+    }
+
+    BOOST_TEST_EQ( count, N * M );
+
+    return boost::report_errors();
+}

test/cfoa/swap_tests.cpp

@@ -190,7 +190,7 @@ namespace {
       map_type x2(vals2.size(), hasher(2), key_equal(1), allocator_type(3));
 
       std::thread t1, t2, t3;
-      boost::latch l(2);
+      boost::compat::latch l(2);
 
       std::mutex m;
       std::condition_variable cv;

test/cfoa/takes_arg_as_cref_tests.cpp

@@ -0,0 +1,178 @@
+// Copyright 2023 Joaquin M Lopez Munoz
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/config.hpp>
+#include <boost/unordered/detail/foa/takes_arg_as_const_reference.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+using boost::unordered::detail::foa::takes_arg_as_const_reference;
+
+using  f1  = void ( const int& );
+void   function2( const int& ) noexcept;
+using  f2  = decltype(function2);
+using  f3  = void ( const int&, char* );
+using  f4  = void ( const int&, ... );
+using  f5  = void ( int& );
+void   function6( int& ) noexcept;
+using  f6  = decltype(function6);
+using  f7  = void ( int&, char* );
+using  f8  = void ( int&, ... );
+struct f9  { void operator()( const int& ); };
+struct f10 { void operator()( const int& ) const; };
+struct f11 { void operator()( const int& ) volatile; };
+struct f12 { void operator()( const int& ) const volatile; };
+struct f13 { void operator()( const int& )&; };
+struct f14 { void operator()( const int& ) const&; };
+struct f15 { void operator()( const int& ) volatile&; };
+struct f16 { void operator()( const int& ) const volatile&; };
+struct f17 { void operator()( const int& )&&; };
+struct f18 { void operator()( const int& ) const&&; };
+struct f19 { void operator()( const int& ) volatile&&; };
+struct f20 { void operator()( const int& ) const volatile&&; };
+struct f21 { void operator()( const int& ) noexcept; };
+struct f22 { void operator()( const int& ) const noexcept; };
+struct f23 { void operator()( const int&, int=0 ); };
+struct f24 { void operator()( const int&, ... ) noexcept; };
+struct f25 { void operator()( int& ); };
+struct f26 { void operator()( int& ) const; };
+struct f27 { void operator()( int& ) volatile; };
+struct f28 { void operator()( int& ) const volatile; };
+struct f29 { void operator()( int& )&; };
+struct f30 { void operator()( int& ) const&; };
+struct f31 { void operator()( int& ) volatile&; };
+struct f32 { void operator()(  int& ) const volatile&; };
+struct f33 { void operator()( int& )&&; };
+struct f34 { void operator()( int& ) const&&; };
+struct f35 { void operator()( int& ) volatile&&; };
+struct f36 { void operator()( int& ) const volatile&&; };
+struct f37 { void operator()( int& ) noexcept; };
+struct f38 { void operator()( int& ) const noexcept; };
+struct f39 { void operator()( int&, int=0 ); };
+struct f40 { void operator()( int&, ... ) noexcept; };
+struct f41 { template<typename Arg> void operator()( const Arg& ); };
+struct f42 { template<typename Arg> void operator()( const Arg& ) const; };
+struct f43 { template<typename Arg> void operator()( const Arg& ) const noexcept; };
+struct f44 { template<typename Arg> void operator()( Arg& ); };
+struct f45 { template<typename Arg> void operator()( Arg& ) const; };
+struct f46 { template<typename Arg> void operator()( Arg& ) const noexcept; };
+struct f47 { template<typename Arg> void operator()( Arg ); };
+struct f48 { template<typename Arg> void operator()( Arg ) const; };
+struct f49 { template<typename Arg> void operator()( Arg ) const noexcept; };
+struct f50
+{
+    void operator()( const int& );
+    void operator()( char* );
+};
+struct f51 // expected false negative
+{
+    void operator()( const int& );
+    template<typename Arg> void operator()( Arg& );
+};
+using f52=int; // detection doesn't crash even if requirements violated
+
+int main()
+{
+    auto  lambda53 = []( const int& ){};
+    using f53=decltype(lambda53);
+    int   retrieved=0;
+    auto  lambda54 = [&]( const int& x ) mutable { retrieved = x; };
+    using f54=decltype(lambda54);
+    auto  lambda55 = []( int& x ){ x = 0; };
+    using f55=decltype(lambda55);
+    auto  lambda56 = [&]( int& x ) mutable { retrieved = x; x = 0; };
+    using f56=decltype(lambda56);
+
+#if !defined(BOOST_NO_CXX14_GENERIC_LAMBDAS)
+    auto  lambda57 = []( const auto& ){};
+    using f57=decltype(lambda57);
+    auto  lambda58 = [&]( const auto& x ) mutable { retrieved = x; };
+    using f58=decltype(lambda58);
+    auto  lambda59 = []( auto& x ){ x = 0; };
+    using f59=decltype(lambda59);
+    auto  lambda60 = [&]( auto& x ) mutable { retrieved = x; x = 0; };
+    using f60=decltype(lambda60);
+#endif
+
+    BOOST_TEST((  takes_arg_as_const_reference<f1,    int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f2,    int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f3,    int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f4,    int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f5,    int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f6,    int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f7,    int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f8,    int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f1*,   int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f2*,   int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f3*,   int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f4*,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f5*,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f6*,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f7*,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f8*,   int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f1&,   int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f2&,   int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f3&,   int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f4&,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f5&,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f6&,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f7&,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f8&,   int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f9,    int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f10,   int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f11,   int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f12,   int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f13&,  int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f14&,  int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f15&,  int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f16&,  int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f17&&, int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f18&&, int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f19&&, int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f20&&, int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f21,   int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f22,   int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f23,   int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f24,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f25,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f26,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f27,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f28,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f29&,  int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f30&,  int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f31&,  int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f32&,  int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f33&&, int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f34&&, int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f35&&, int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f36&&, int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f37,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f38,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f39,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f40,   int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f41,   int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f42,   int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f43,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f44,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f45,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f46,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f47,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f48,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f49,   int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f50,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f51,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f52,   int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f53,   int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f54,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f55,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f56,   int>::value ));
+
+#if !defined(BOOST_NO_CXX14_GENERIC_LAMBDAS)
+    BOOST_TEST((  takes_arg_as_const_reference<f57,   int>::value ));
+    BOOST_TEST((  takes_arg_as_const_reference<f58,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f59,   int>::value ));
+    BOOST_TEST(( !takes_arg_as_const_reference<f60,   int>::value ));
+#endif
+
+    return boost::report_errors();
+}

test/cfoa/visit_tests.cpp

@@ -520,7 +520,7 @@ namespace {
       X x;
 
       std::thread t1, t2;
-      boost::latch l(2);
+      boost::compat::latch l(2);
       std::vector<std::string> strs(values.size());
 
       t1 = std::thread([&l, &values, &x, &strs] {