xo-object2: GCObjectConversion for double (via DFloat)

include/xo/object2/number/GCObjectConversion_DFloat.hpp

@@ -0,0 +1,29 @@
+/** @file GCObjectConversion_DFloat.hpp
+ *
+ *  @author Roland Conybeare, Jan 2026
+ **/
+
+#pragma once
+
+#include "DFloat.hpp"
+#include "number/IGCObject_DFloat.hpp"
+#include <xo/gc/GCObjectConversion.hpp>
+
+namespace xo {
+    namespace scm {
+
+        template <>
+        struct GCObjectConversion<double> {
+            static_assert(std::is_same_v<double, DFloat::value_type>);
+
+            using AGCObject = xo::mm::AGCObject;
+            using AAllocator = xo::mm::AAllocator;
+
+            static obj<AGCObject> to_gco(obj<AAllocator> mm, const double & x);
+            static double from_gco(obj<AAllocator> mm, obj<AGCObject> gco);
+        };
+
+    } /*namespace scm*/
+} /*namespace xo*/
+
+/* end GCObjectConversion_DFloat.hpp */