Small shared n-way pointer

This replaces small_shared_two_way_ptrt with small_shared_n_way_ptrt. The new
shared pointer type allows more than two types for the managed objects. This can
be useful e.g. for implementing graph data structures with sharing where there
are more than two different node types.

Author: danpoe

src/util/sharing_node.h

@@ -35,8 +35,8 @@ Author: Daniel Poetzl
 
 #include "invariant.h"
 #include "make_unique.h"
+#include "small_shared_n_way_ptr.h"
 #include "small_shared_ptr.h"
-#include "small_shared_two_way_ptr.h"
 
 #ifdef SN_INTERNAL_CHECKS
 #define SN_ASSERT(b) INVARIANT(b, "Sharing node internal invariant")
@@ -70,7 +70,7 @@ const T *as_const(T *t)
 
 // Inner nodes (internal nodes or container nodes)
 
-typedef small_shared_two_way_pointeet<unsigned> d_baset;
+typedef small_shared_n_way_pointee_baset<2, unsigned> d_baset;
 
 SN_TYPE_PAR_DECL class sharing_node_innert;
 
@@ -105,7 +105,7 @@ class sharing_node_baset
 SN_TYPE_PAR_DEF class sharing_node_innert : public sharing_node_baset
 {
 public:
-  typedef small_shared_two_way_ptrt<SN_PTR_TYPE_ARGS> datat;
+  typedef small_shared_n_way_ptrt<SN_PTR_TYPE_ARGS> datat;
   typedef typename datat::use_countt use_countt;
 
   typedef d_internalt<SN_TYPE_ARGS> d_it;
@@ -155,12 +155,12 @@ SN_TYPE_PAR_DEF class sharing_node_innert : public sharing_node_baset
 
   bool is_internal() const
   {
-    return data.is_derived_u();
+    return data.template is_derived<0>();
   }
 
   bool is_container() const
   {
-    return data.is_derived_v();
+    return data.template is_derived<1>();
   }
 
   bool is_defined_internal() const
@@ -177,14 +177,14 @@ SN_TYPE_PAR_DEF class sharing_node_innert : public sharing_node_baset
   {
     SN_ASSERT(!empty());
 
-    return *data.get_derived_u();
+    return *data.template get_derived<0>();
   }
 
   const d_ct &read_container() const
   {
     SN_ASSERT(!empty());
 
-    return *data.get_derived_v();
+    return *data.template get_derived<1>();
   }
 
   // Accessors
@@ -334,32 +334,34 @@ SN_TYPE_PAR_DEF class sharing_node_innert : public sharing_node_baset
   {
     if(!data)
     {
-      data = make_shared_derived_u<SN_PTR_TYPE_ARGS>();
+      data = make_shared_2<0, SN_PTR_TYPE_ARGS>();
     }
     else if(data.use_count() > 1)
     {
-      data = make_shared_derived_u<SN_PTR_TYPE_ARGS>(*data.get_derived_u());
+      data =
+        make_shared_2<0, SN_PTR_TYPE_ARGS>(*data.template get_derived<0>());
     }
 
     SN_ASSERT(data.use_count() == 1);
 
-    return *data.get_derived_u();
+    return *data.template get_derived<0>();
   }
 
   d_ct &write_container()
   {
     if(!data)
     {
-      data = make_shared_derived_v<SN_PTR_TYPE_ARGS>();
+      data = make_shared_2<1, SN_PTR_TYPE_ARGS>();
     }
     else if(data.use_count() > 1)
     {
-      data = make_shared_derived_v<SN_PTR_TYPE_ARGS>(*data.get_derived_v());
+      data =
+        make_shared_2<1, SN_PTR_TYPE_ARGS>(*data.template get_derived<1>());
     }
 
     SN_ASSERT(data.use_count() == 1);
 
-    return *data.get_derived_v();
+    return *data.template get_derived<1>();
   }
 
   datat data;