xo-gc stack: streamline object pointer forwarding

idl/GCObject.json5

@@ -76,5 +76,5 @@
             attributes: [],
         },
     ],
-    router_facet_explicit_content: [ ],
+    router_facet_explicit_content: []
 }

include/xo/gc/GCObject.hpp

@@ -18,5 +18,31 @@
 #include "detail/IGCObject_Xfer.hpp"
 #include "detail/RGCObject.hpp"
 
+namespace xo {
+    namespace mm {
+        /** defined here to avoid #include cycle, since
+         *  template obj<AGCObject,DRepr> awkward to make available there
+         **/
+        template <typename Object>
+        template <typename DRepr>
+        void
+        RCollector<Object>::forward_inplace(xo::facet::obj<AGCObject,DRepr> * p_obj)
+        {
+            this->forward_inplace(p_obj->iface(), (void **)&(p_obj->data_));
+        }
+
+        template <typename Object>
+        template <typename DRepr>
+        void
+        RCollector<Object>::forward_inplace(DRepr ** p_repr)
+        {
+            // fetch static interface for DRepr
+            auto iface = xo::facet::impl_for<AGCObject,DRepr>();
+
+            this->forward_inplace(&iface, (void **)p_repr);
+        }
+    }
+}
+
+/* end GCObject.hpp */
 
-/* end GCObject.hpp */

include/xo/gc/detail/RCollector.hpp

@@ -23,6 +23,16 @@ namespace xo {
             RCollector() = default;
             RCollector(DataPtr data) : Object{std::move(data)} {}
 
+            /** forward op in place. Defined in GCObject.hpp to avoid #include cycle **/
+            template <typename DRepr>
+            void forward_inplace(obj<AGCObject,DRepr> * p_obj);
+
+            /** another convenience template for forwarding.
+             *  Defined in RGCObject.hpp to avoid #include cycle.
+             **/
+            template <typename DRepr>
+            void forward_inplace(DRepr ** pp_repr);
+
             int32_t _typeseq() const noexcept { return O::iface()->_typeseq(); }
             size_type allocated(generation g, role r) const noexcept { return O::iface()->allocated(O::data(), g, r); }
             size_type reserved(generation g, role r) const noexcept { return O::iface()->reserved(O::data(), g, r); }