diff --git a/doc/intrusive.qbk b/doc/intrusive.qbk
index ac63361..f440928 100644
--- a/doc/intrusive.qbk
+++ b/doc/intrusive.qbk
@@ -3839,6 +3839,7 @@ to be inserted in intrusive containers are allocated using `std::vector` or `std
 
 *  Fixed bugs:
    *  [@https://svn.boost.org/trac/boost/ticket/12190 Boost Trac #12190: ['Intrusive List + Flat Map combination crashes]]
+   *  [@https://svn.boost.org/trac/boost/ticket/12245 Boost Trac #12245: ['bstree uses a shared static size_traits for constant_time_size<false>]]
 
 [endsect]
 
diff --git a/include/boost/intrusive/bstree.hpp b/include/boost/intrusive/bstree.hpp
index 0fb9218..a5f20a7 100644
--- a/include/boost/intrusive/bstree.hpp
+++ b/include/boost/intrusive/bstree.hpp
@@ -554,18 +554,10 @@ struct bstbase_hack<ValueTraits, VoidOrKeyOfValue, VoidOrKeyComp, false, SizeTyp
 
    typedef detail::size_holder<false, SizeType>     size_traits;
 
-   size_traits &sz_traits()
-   {  return s_size_traits;  }
-
-   const size_traits &sz_traits() const
-   {  return s_size_traits;  }
-
-   static size_traits s_size_traits;
+   size_traits sz_traits() const
+   {  return size_traits();  }
 };
 
-template<class ValueTraits, class VoidOrKeyOfValue, class VoidOrKeyComp, class SizeType, algo_types AlgoType, typename HeaderHolder>
-detail::size_holder<false, SizeType> bstbase_hack<ValueTraits, VoidOrKeyOfValue, VoidOrKeyComp, false, SizeType, AlgoType, HeaderHolder>::s_size_traits;
-
 //This class will
 template<class ValueTraits, class VoidOrKeyOfValue, class VoidOrKeyComp, bool ConstantTimeSize, class SizeType, algo_types AlgoType, typename HeaderHolder>
 struct bstbase
@@ -955,11 +947,7 @@ class bstree_impl
       ::boost::adl_move_swap(this->comp(), this->comp());
       //These can't throw
       node_algorithms::swap_tree(this->header_ptr(), node_ptr(other.header_ptr()));
-      if(constant_time_size){
-         size_type backup = this->sz_traits().get_size();
-         this->sz_traits().set_size(other.sz_traits().get_size());
-         other.sz_traits().set_size(backup);
-      }
+      this->sz_traits().swap(other.sz_traits());
    }
 
    //! <b>Requires</b>: Disposer::operator()(pointer) shouldn't throw.
diff --git a/include/boost/intrusive/detail/size_holder.hpp b/include/boost/intrusive/detail/size_holder.hpp
index 9802ac3..bd14dc5 100644
--- a/include/boost/intrusive/detail/size_holder.hpp
+++ b/include/boost/intrusive/detail/size_holder.hpp
@@ -51,6 +51,9 @@ struct size_holder
    BOOST_INTRUSIVE_FORCEINLINE void decrease(SizeType n)
    {  size_ -= n; }
 
+   BOOST_INTRUSIVE_FORCEINLINE void swap(size_holder &other)
+   {  SizeType tmp(size_); size_ = other.size_; other.size_ = tmp; }
+
    SizeType size_;
 };
 
@@ -77,6 +80,8 @@ struct size_holder<false, SizeType, Tag>
 
    BOOST_INTRUSIVE_FORCEINLINE void decrease(SizeType)
    {}
+
+   BOOST_INTRUSIVE_FORCEINLINE void swap(size_holder){}
 };
 
 }  //namespace detail{
diff --git a/include/boost/intrusive/hashtable.hpp b/include/boost/intrusive/hashtable.hpp
index f9074c0..4a8e9a8 100644
--- a/include/boost/intrusive/hashtable.hpp
+++ b/include/boost/intrusive/hashtable.hpp
@@ -119,6 +119,8 @@ struct prime_list_holder
    static const std::size_t prime_list_size;
 };
 
+#if !defined(BOOST_INTRUSIVE_DOXYGEN_INVOKED)
+
 //We only support LLP64(Win64) or LP64(most Unix) data models
 #ifdef _WIN64  //In 64 bit windows sizeof(size_t) == sizeof(unsigned long long)
    #define BOOST_INTRUSIVE_PRIME_C(NUMBER) NUMBER##ULL
@@ -173,6 +175,8 @@ const std::size_t prime_list_holder<Dummy>::prime_list[] = {
 #undef BOOST_INTRUSIVE_PRIME_C
 #undef BOOST_INTRUSIVE_64_BIT_SIZE_T
 
+#endif   //#if !defined(BOOST_INTRUSIVE_DOXYGEN_INVOKED)
+
 template<int Dummy>
 const std::size_t prime_list_holder<Dummy>::prime_list_size
    = sizeof(prime_list)/sizeof(std::size_t);
@@ -1243,10 +1247,13 @@ struct hashtable_size_traits_wrapper
 
    size_traits size_traits_;
 
-   const size_traits &priv_size_traits() const
+   typedef const size_traits & size_traits_const_t;
+   typedef       size_traits & size_traits_t;
+
+   size_traits_const_t priv_size_traits() const
    {  return size_traits_; }
 
-   size_traits &priv_size_traits()
+   size_traits_t priv_size_traits()
    {  return size_traits_; }
 };
 
@@ -1265,18 +1272,13 @@ struct hashtable_size_traits_wrapper<DeriveFrom, SizeType, false>
 
    typedef detail::size_holder< false, SizeType>   size_traits;
 
-   const size_traits &priv_size_traits() const
-   {  return size_traits_; }
+   typedef size_traits size_traits_const_t;
+   typedef size_traits size_traits_t;
 
-   size_traits &priv_size_traits()
-   {  return size_traits_; }
-
-   static size_traits size_traits_;
+   BOOST_INTRUSIVE_FORCEINLINE size_traits priv_size_traits() const
+   {  return size_traits(); }
 };
 
-template<class DeriveFrom, class SizeType>
-detail::size_holder< false, SizeType > hashtable_size_traits_wrapper<DeriveFrom, SizeType, false>::size_traits_;
-
 //hashdata_internal
 //Stores bucket_hash_equal_t and split_traits
 template<class ValueTraits, class VoidOrKeyOfValue, class VoidOrKeyHash, class VoidOrKeyEqual, class BucketTraits, class SizeType, std::size_t BoolFlags>
@@ -1360,10 +1362,10 @@ struct hashdata_internal
       :  internal_type(val_traits, ::boost::forward<BucketTraitsType>(b_traits), h, e)
    {}
 
-   split_traits &priv_split_traits()
+   BOOST_INTRUSIVE_FORCEINLINE typename internal_type::size_traits_t priv_split_traits()
    {  return this->priv_size_traits();  }
 
-   const split_traits &priv_split_traits() const
+   BOOST_INTRUSIVE_FORCEINLINE typename internal_type::size_traits_const_t priv_split_traits() const
    {  return this->priv_size_traits();  }
 
    ~hashdata_internal()
@@ -1790,15 +1792,10 @@ class hashtable_impl
    {
       this->priv_swap_cache(x);
       x.priv_initialize_cache();
-      if(constant_time_size){
-         this->priv_size_traits().set_size(size_type(0));
-         this->priv_size_traits().set_size(x.priv_size_traits().get_size());
-         x.priv_size_traits().set_size(size_type(0));
-      }
-      if(incremental){
-         this->priv_split_traits().set_size(x.priv_split_traits().get_size());
-         x.priv_split_traits().set_size(size_type(0));
-      }
+      this->priv_size_traits().set_size(x.priv_size_traits().get_size());
+      x.priv_size_traits().set_size(size_type(0));
+      this->priv_split_traits().set_size(x.priv_split_traits().get_size());
+      x.priv_split_traits().set_size(size_type(0));
    }
 
    //! <b>Effects</b>: to-do
@@ -1946,8 +1943,8 @@ class hashtable_impl
       ::boost::adl_move_swap(this->priv_bucket_traits(), other.priv_bucket_traits());
       ::boost::adl_move_swap(this->priv_value_traits(), other.priv_value_traits());
       this->priv_swap_cache(other);
-      ::boost::adl_move_swap(this->priv_size_traits(), other.priv_size_traits());
-      ::boost::adl_move_swap(this->priv_split_traits(), other.priv_split_traits());
+      this->priv_size_traits().swap(other.priv_size_traits());
+      this->priv_split_traits().swap(other.priv_split_traits());
    }
 
    //! <b>Requires</b>: Disposer::operator()(pointer) shouldn't throw
diff --git a/include/boost/intrusive/list.hpp b/include/boost/intrusive/list.hpp
index a59734a..a955c44 100644
--- a/include/boost/intrusive/list.hpp
+++ b/include/boost/intrusive/list.hpp
@@ -542,11 +542,7 @@ class list_impl
    void swap(list_impl& other)
    {
       node_algorithms::swap_nodes(this->get_root_node(), other.get_root_node());
-      if(constant_time_size){
-         size_type backup = this->priv_size_traits().get_size();
-         this->priv_size_traits().set_size(other.priv_size_traits().get_size());
-         other.priv_size_traits().set_size(backup);
-      }
+      this->priv_size_traits().swap(other.priv_size_traits());
    }
 
    //! <b>Effects</b>: Moves backwards all the elements, so that the first
diff --git a/include/boost/intrusive/slist.hpp b/include/boost/intrusive/slist.hpp
index cf8da58..5ce9329 100644
--- a/include/boost/intrusive/slist.hpp
+++ b/include/boost/intrusive/slist.hpp
@@ -716,11 +716,7 @@ class slist_impl
       else{
          this->priv_swap_lists(this->get_root_node(), other.get_root_node(), detail::bool_<linear>());
       }
-      if(constant_time_size){
-         size_type backup = this->priv_size_traits().get_size();
-         this->priv_size_traits().set_size(other.priv_size_traits().get_size());
-         other.priv_size_traits().set_size(backup);
-      }
+      this->priv_size_traits().swap(other.priv_size_traits());
    }
 
    //! <b>Effects</b>: Moves backwards all the elements, so that the first