Feature/concurrent node containers (#271)

* added concurrent node containers

* removed spurious typename

* added missing includes

* avoided unused param warning

* worked around Clang bug

* s/{}/() to work around GCC4.8 problems with aggregate initialization

* used /bigobj for cfoa/visit_tests.cpp

* suppressed localized maybe-uninitialized warnings

* fixed comments

* added /bigobj to cfoa/insert_tests.cpp

* instrumented double exact comparison to spot a spurious error

* fixed pedantic error

* refactored byte_span machinery

* compromised on sub-epsilon equality for doubles that should be identical

* documented boost::concurrent_node_(map|set)

* added concurrent_node_set

* added missing AlternativeType

* tested empty node insertion

* tested node_handle allocator management

* added nonassignable_allocator and node_handle_allocator_swap_tests

* fixed warning disabling

* silenced spurious GCC warning

* broadened scope of previous pragma

* broadened even more

* worked around spurious constexpr-related msvc-14.0 bug
https://godbolt.org/z/v78545Ebf

* added workaround back

* replaced previous workaround with built-in one

* added workaround back on top of built-in solution (which doesn't work 100% of the time)

test/cfoa/equality_tests.cpp

@@ -1,5 +1,5 @@
 // Copyright (C) 2023 Christian Mazakas
-// Copyright (C) 2023 Joaquin M Lopez Munoz
+// Copyright (C) 2023-2024 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)
 
@@ -7,6 +7,8 @@
 
 #include <boost/unordered/concurrent_flat_map.hpp>
 #include <boost/unordered/concurrent_flat_set.hpp>
+#include <boost/unordered/concurrent_node_map.hpp>
+#include <boost/unordered/concurrent_node_set.hpp>
 
 test::seed_t initialize_seed{1634048962};
 
@@ -20,28 +22,38 @@ using key_equal = stateful_key_equal;
 using map_type = boost::unordered::concurrent_flat_map<raii, raii, hasher,
   key_equal, stateful_allocator<std::pair<raii const, raii> > >;
 
+using node_map_type = boost::unordered::concurrent_node_map<raii, raii, hasher,
+  key_equal, stateful_allocator<std::pair<raii const, raii> > >;
+
 using set_type = boost::unordered::concurrent_flat_set<raii, hasher,
   key_equal, stateful_allocator<raii> >;
 
+using node_set_type = boost::unordered::concurrent_node_set<raii, hasher,
+  key_equal, stateful_allocator<raii> >;
+
 map_type* test_map;
+node_map_type* test_node_map;
 set_type* test_set;
+node_set_type* test_node_set;
 
 namespace {
 
-  UNORDERED_AUTO_TEST (simple_map_equality) {
-    using allocator_type = map_type::allocator_type;
+  template <class X>
+  void simple_map_equality(X*)
+  {
+    using allocator_type = typename X::allocator_type;
 
     {
-      map_type x1(
+      X x1(
         {{1, 11}, {2, 22}}, 0, hasher(1), key_equal(2), allocator_type(3));
 
-      map_type x2(
+      X x2(
         {{1, 11}, {2, 22}}, 0, hasher(2), key_equal(2), allocator_type(3));
 
-      map_type x3(
+      X x3(
         {{1, 11}, {2, 23}}, 0, hasher(2), key_equal(2), allocator_type(3));
 
-      map_type x4({{1, 11}}, 0, hasher(2), key_equal(2), allocator_type(3));
+      X x4({{1, 11}}, 0, hasher(2), key_equal(2), allocator_type(3));
 
       BOOST_TEST_EQ(x1.size(), x2.size());
       BOOST_TEST(x1 == x2);
@@ -57,17 +69,19 @@ namespace {
     }
   }
 
-  UNORDERED_AUTO_TEST (simple_set_equality) {
-    using allocator_type = set_type::allocator_type;
+  template <class X>
+  void simple_set_equality(X*)
+  {
+    using allocator_type = typename X::allocator_type;
 
     {
-      set_type x1(
+      X x1(
         {1, 2}, 0, hasher(1), key_equal(2), allocator_type(3));
 
-      set_type x2(
+      X x2(
         {1, 2}, 0, hasher(2), key_equal(2), allocator_type(3));
 
-      set_type x3({1}, 0, hasher(2), key_equal(2), allocator_type(3));
+      X x3({1}, 0, hasher(2), key_equal(2), allocator_type(3));
 
       BOOST_TEST_EQ(x1.size(), x2.size());
       BOOST_TEST(x1 == x2);
@@ -165,9 +179,17 @@ namespace {
 } // namespace
 
 // clang-format off
+UNORDERED_TEST(
+  simple_map_equality,
+  ((test_map)(test_node_map)))
+
+UNORDERED_TEST(
+  simple_set_equality,
+  ((test_set)(test_node_set)))
+
 UNORDERED_TEST(
   insert_and_compare,
-  ((test_map)(test_set))
+  ((test_map)(test_node_map)(test_set)(test_node_set))
   ((value_type_generator_factory))
   ((default_generator)(sequential)(limited_range)))
 // clang-format on