From 1e61423eac8fb9fd2c00640f9e3f7667a400fddd Mon Sep 17 00:00:00 2001
From: Christian Mazakas <christian.mazakas@gmail.com>
Date: Wed, 11 Jan 2023 13:02:04 -0800
Subject: [PATCH] Prove relevance of strong typedef for node-based foa
 containers

---
 .../boost/unordered/unordered_node_set.hpp    | 61 ++-----------------
 test/unordered/insert_tests.cpp               |  7 ++-
 2 files changed, 9 insertions(+), 59 deletions(-)

diff --git a/include/boost/unordered/unordered_node_set.hpp b/include/boost/unordered/unordered_node_set.hpp
index 56325162..5457f40f 100644
--- a/include/boost/unordered/unordered_node_set.hpp
+++ b/include/boost/unordered/unordered_node_set.hpp
@@ -40,65 +40,15 @@ namespace boost {
 
         static Key const& extract(value_type const& key) { return key; }
 
-#if 0
-        using element_type = value_type*;
-        static value_type& value_from(element_type& x) { return *x; }
-
-        static Key const& extract(element_type k) { return *k; }
-        static element_type&& move(element_type& x) { return std::move(x); }
-
-        template <class A>
-        static void construct(A&, element_type* p, element_type&& x)
-        {
-          *p = x;
-          x = nullptr;
-        }
-
-        template <class A, class... Args>
-        static void construct(A& al, element_type* p, element_type const& x)
-        {
-          *p = boost::to_address(boost::allocator_allocate(al, 1));
-          try {
-            boost::allocator_construct(al, *p, *x);
-          } catch (...) {
-            boost::allocator_deallocate(al,
-              boost::pointer_traits<
-                typename boost::allocator_pointer<A>::type>::pointer_to(**p),
-              1);
-            throw;
-          }
-        }
-
-        template <class A, class... Args>
-        static void construct(A& al, element_type* p, Args&&... args)
-        {
-          *p = boost::to_address(boost::allocator_allocate(al, 1));
-          try {
-            boost::allocator_construct(al, *p, std::forward<Args>(args)...);
-          } catch (...) {
-            boost::allocator_deallocate(al,
-              boost::pointer_traits<
-                typename boost::allocator_pointer<A>::type>::pointer_to(**p),
-              1);
-            throw;
-          }
-        }
-
-        template <class A> static void destroy(A& al, element_type* p) noexcept
-        {
-          if (*p) {
-            boost::allocator_destroy(al, *p);
-            boost::allocator_deallocate(al,
-              boost::pointer_traits<
-                typename boost::allocator_pointer<A>::type>::pointer_to(**p),
-              1);
-          }
-        }
-#else
         struct element_type
         {
           value_type* p;
 
+          /*
+           * we use a defined copy constructor here so the type is no longer
+           * trivially copy-constructible which inhibits our memcpy
+           * optimizations when copying the tables
+           */
           element_type() : p(nullptr) {}
           element_type(element_type const& rhs) : p(rhs.p) {}
         };
@@ -146,7 +96,6 @@ namespace boost {
               1);
           }
         }
-#endif
       };
     } // namespace detail
 
diff --git a/test/unordered/insert_tests.cpp b/test/unordered/insert_tests.cpp
index 3e0bce7d..446e286a 100644
--- a/test/unordered/insert_tests.cpp
+++ b/test/unordered/insert_tests.cpp
@@ -701,7 +701,7 @@ namespace insert_tests {
     pointer_constructible(int x_) : x(x_) {}
     pointer_constructible(pointer_constructible const& p) : x(p.x) {}
     pointer_constructible(pointer_constructible* const&) : x(-1) {}
-    pointer_constructible(BOOST_RV_REF(pointer_constructible*)) : x(-2) {}
+    pointer_constructible(BOOST_RV_REF(pointer_constructible*)) : x(-1) {}
   };
 
   struct pointer_constructible_hash
@@ -733,11 +733,12 @@ namespace insert_tests {
       pointer_constructible_equal_to, test::allocator1<pointer_constructible> >
       set, set2;
 
-    pointer_constructible pc(1337), *addr_pc = &pc;
+    pointer_constructible pc(1337);
+    pointer_constructible* const addr_pc = &pc;
 
     set.insert(pc);      // 1337
-    set.insert(addr_pc); // -1
     set.insert(&pc);     // -1
+    set.insert(addr_pc); // -1
 
     BOOST_TEST_EQ(set.size(), 2u);
     BOOST_TEST(set.find(pc) != set.end());