xo-gc: + GCObjectConversion template

include/xo/gc/GCObjectConversion.hpp

@@ -0,0 +1,30 @@
+/** @file GCObjectConversion.hpp
+ *
+ *  @author Roland Conybeare, Jan 2026
+ **/
+
+#pragma once
+
+#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/Allocator.hpp>
+
+namespace xo {
+    namespace scm {
+        /** @brief compile-time conversion obj<AGCObject> <-> T
+         *
+         *  Specialize for each T that participates in conversion.
+         *  Methods here aren't implemented
+         **/
+        template <typename T>
+        struct GCObjectConversion {
+            using AGCObject = xo::mm::AGCObject;
+            using AAllocator = xo::mm::AAllocator;
+
+            static obj<AGCObject> to_gco(obj<AAllocator> mm, const T & x);
+            static T from_gco(obj<AAllocator> mm, obj<AGCObject> gco);
+        };
+
+    } /*namespace scm */
+} /*namespace xo*/
+
+/* end GCObjectConversion.hpp */